/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --dark-color: #1e293b;
    --light-color: #f8fafc;
    --text-color: #334155;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --gradient: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    --gradient-1: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    --gradient-2: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
    --gradient-3: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%);
    --gradient-4: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
    --shadow-xl: 0 16px 48px rgba(0,0,0,0.16);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Smooth Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes gradient-shift {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* Header & Navigation */
.header {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    box-shadow: 0 2px 30px rgba(0,0,0,0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.3s ease;
}

.header.scrolled {
    box-shadow: 0 4px 40px rgba(0,0,0,0.12);
    background: rgba(255, 255, 255, 1);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
    max-width: 1400px;
    margin: 0 auto;
}

/* Brand Styles */
.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    transition: transform 0.3s ease;
}

.nav-brand:hover {
    transform: translateY(-2px);
}

.brand-icon {
    width: 42px;
    height: 42px;
    background: var(--gradient);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    transition: all 0.3s ease;
}

.nav-brand:hover .brand-icon {
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
    transform: rotate(-5deg);
}

.brand-icon svg {
    width: 24px;
    height: 24px;
    color: white;
}

.brand-text {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.brand-badge {
    padding: 0.25rem 0.65rem;
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
    font-size: 0.7rem;
    font-weight: 700;
    border-radius: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: 0 2px 8px rgba(16, 185, 129, 0.3);
}

/* Navigation Menu */
.nav-menu {
    display: flex;
    list-style: none;
    gap: 0.5rem;
    align-items: center;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 0.65rem 1.25rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    font-size: 0.95rem;
    border-radius: 10px;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link svg {
    width: 18px;
    height: 18px;
    transition: all 0.3s ease;
}

.nav-link:hover {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    color: var(--primary-color);
    transform: translateY(-2px);
}

.nav-link:hover svg {
    transform: scale(1.1);
}

.nav-link.active {
    background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%);
    color: var(--primary-color);
    box-shadow: 0 2px 10px rgba(99, 102, 241, 0.2);
}

.nav-link.active svg {
    color: var(--primary-color);
}

/* Navigation Badge */
.nav-badge {
    padding: 0.2rem 0.5rem;
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    color: white;
    font-size: 0.65rem;
    font-weight: 700;
    border-radius: 6px;
    margin-left: 4px;
    box-shadow: 0 2px 6px rgba(251, 191, 36, 0.3);
}

/* CTA Link */
.nav-link-cta {
    background: var(--gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    margin-left: 0.5rem;
}

.nav-link-cta:hover {
    background: linear-gradient(135deg, #5a67d8 0%, #6b46c1 100%);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.nav-link-cta svg {
    color: white;
}

/* Mobile Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: background 0.3s ease;
    -webkit-tap-highlight-color: transparent;
}

.nav-toggle:hover {
    background: #f1f5f9;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--dark-color);
    border-radius: 2px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    transform-origin: center;
    will-change: transform, opacity;
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
    transform: scale(0);
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* Responsive Navigation */
@media (max-width: 968px) {
    .nav-menu {
        position: fixed;
        left: 0;
        top: 70px;
        flex-direction: column;
        background: white;
        width: 100%;
        height: calc(100vh - 70px);
        text-align: center;
        box-shadow: 0 10px 40px rgba(0,0,0,0.1);
        padding: 2rem 0;
        gap: 0;
        opacity: 0;
        visibility: hidden;
        transition: opacity 0.25s ease, visibility 0.25s ease;
        overflow-y: auto;
        z-index: 999;
        -webkit-overflow-scrolling: touch;
    }

    .nav-menu.active {
        opacity: 1;
        visibility: visible;
    }

    .nav-link {
        width: 100%;
        justify-content: center;
        padding: 1rem 2rem;
        border-radius: 0;
    }

    .nav-link-cta {
        margin: 1rem 2rem 0;
        width: calc(100% - 4rem);
        border-radius: 10px;
    }

    .nav-toggle {
        display: flex;
        z-index: 1001;
    }

    .brand-text {
        font-size: 1.3rem;
    }

    .brand-icon {
        width: 38px;
        height: 38px;
    }

    .brand-icon svg {
        width: 20px;
        height: 20px;
    }

    /* Prevent body scroll when menu is open */
    body.menu-open {
        overflow: hidden;
    }

     

    .nav-menu.active::before {
        opacity: 1;
        pointer-events: auto;
    }
}

/* Hero Section */
.hero {
    position: relative;
    background: #7c3aed !important;
    color: white;
    padding: 100px 0 0;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 0;
    pointer-events: none;
}

.hero-pattern {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(30deg, rgba(255,255,255,0.08) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.08) 87.5%, rgba(255,255,255,0.08)),
        linear-gradient(150deg, rgba(255,255,255,0.08) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.08) 87.5%, rgba(255,255,255,0.08)),
        linear-gradient(30deg, rgba(255,255,255,0.08) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.08) 87.5%, rgba(255,255,255,0.08)),
        linear-gradient(150deg, rgba(255,255,255,0.05) 12%, transparent 12.5%, transparent 87%, rgba(255,255,255,0.05) 87.5%, rgba(255,255,255,0.05));
    background-size: 80px 140px;
    background-position: 0 0, 0 0, 40px 70px, 40px 70px;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0;
    animation: float 10s ease-in-out infinite;
    display: none;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: rgba(236, 72, 153, 0.4);
    top: -150px;
    right: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 600px;
    height: 600px;
    background: rgba(99, 102, 241, 0.3);
    bottom: -200px;
    left: -200px;
    animation-delay: 3s;
}

.orb-3 {
    width: 400px;
    height: 400px;
    background: rgba(139, 92, 246, 0.4);
    top: 40%;
    left: 40%;
    animation-delay: 6s;
}

.hero-content {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    padding-bottom: 4rem;
    /* padding: 20px 0; */
}

.hero-left {
    animation: fadeInUp 0.8s ease-out;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 24px;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border-radius: 50px;
    border: 1px solid rgba(255, 255, 255, 0.25);
    font-size: 0.9rem;
    margin-bottom: 2rem;
    font-weight: 500;
    color: white;
}

.badge-icon {
    width: 18px;
    height: 18px;
    color: #fbbf24;
}

.hero-title {
    font-size: 4.5rem;
    margin-bottom: 1.5rem;
    font-weight: 900;
    line-height: 1.1;
    color: white;
}

.gradient-text {
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
}

.hero-subtitle {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    line-height: 1.8;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.inline-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    margin-top: 2px;
}

.hero-search {
    max-width: 550px;
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    border-radius: 60px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0,0,0,0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 6px 6px 6px 24px;
    margin-bottom: 2.5rem;
}

.search-icon {
    width: 22px;
    height: 22px;
    color: var(--primary-color);
    margin-right: 12px;
    flex-shrink: 0;
}

.hero-search input {
    flex: 1;
    padding: 1rem 0;
    border: none;
    font-size: 1rem;
    outline: none;
    background: transparent;
    color: var(--dark-color);
}

.hero-search input::placeholder {
    color: #94a3b8;
}

.search-btn {
    padding: 1rem 2rem;
    background: var(--gradient);
    border: none;
    color: white;
    cursor: pointer;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: all 0.3s;
}

.search-btn svg {
    width: 18px;
    height: 18px;
}

.search-btn:hover {
    transform: translateX(5px);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.4);
}

.hero-features {
    display: flex;
    gap: 2rem;
}

.hero-feature {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(10px);
    border-radius: 50px;
    border: 1px solid rgba(255, 255, 255, 0.25);
    font-size: 0.9rem;
    font-weight: 500;
    color: white;
}

.hero-feature svg {
    width: 20px;
    height: 20px;
}

.hero-right {
    position: relative;
    height: 500px;
    animation: fadeInUp 0.8s ease-out 0.3s both;
}

.hero-visual {
    position: relative;
    width: 100%;
    height: 100%;
}

/* 添加连接线动画 */
@keyframes drawLine {
    from {
        stroke-dashoffset: 1000;
    }
    to {
        stroke-dashoffset: 0;
    }
}

.floating-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(40px);
    border: 1.5px solid rgba(255, 255, 255, 0.3);
    border-radius: 28px;
    padding: 2rem 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.15);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    animation: float 10s ease-in-out infinite;
    cursor: pointer;
    color: white;
}
    

/* 添加光泽效果 */
.floating-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(
        45deg,
        transparent 30%,
        rgba(255, 255, 255, 0.1) 50%,
        transparent 70%
    );
    transform: rotate(45deg);
    transition: all 0.6s;
}

.floating-card:hover::before {
    left: 100%;
}

.floating-card:hover {
    transform: translateY(-15px) scale(1.08);
    background: rgba(255, 255, 255, 0.25);
    box-shadow: 0 25px 80px rgba(0,0,0,0.3),
                inset 0 1px 0 rgba(255,255,255,0.4);
    border-color: rgba(255, 255, 255, 0.5);
}

.floating-card svg {
    width: 52px;
    height: 52px;
    stroke-width: 1.8;
    filter: drop-shadow(0 4px 12px rgba(0,0,0,0.2));
    transition: transform 0.4s;
}

.floating-card:hover svg {
    transform: scale(1.15) rotate(5deg);
}

.floating-card span {
    font-size: 1rem;
    font-weight: 800;
    letter-spacing: 0.5px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* 优化卡片位置，更好的分布 */
.card-1 {
    top: 8%;
    left: 5%;
    animation-delay: 0s;
}

.card-2 {
    top: 12%;
    right: 5%;
    animation-delay: 2.5s;
}

.card-3 {
    bottom: 22%;
    left: 3%;
    animation-delay: 5s;
}

.card-4 {
    bottom: 12%;
    right: 8%;
    animation-delay: 7.5s;
}

/* 增强中心图标 */
.hero-visual-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 160px;
    height: 160px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.25) 0%, rgba(255, 255, 255, 0.15) 100%);
    backdrop-filter: blur(40px);
    border: 3px solid rgba(255, 255, 255, 0.4);
    border-radius: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 30px 90px rgba(0,0,0,0.3), 
                inset 0 2px 0 rgba(255,255,255,0.4),
                inset 0 -2px 0 rgba(0,0,0,0.1);
    animation: pulse 5s ease-in-out infinite, rotate3d 20s linear infinite;
    position: relative;
    overflow: hidden;
}

/* 3D旋转动画 */
@keyframes rotate3d {
    0% {
        transform: translate(-50%, -50%) perspective(1000px) rotateY(0deg);
    }
    100% {
        transform: translate(-50%, -50%) perspective(1000px) rotateY(360deg);
    }
}

/* 光晕效果 */
.hero-visual-center::after {
    content: '';
    position: absolute;
    inset: -20px;
    background: radial-gradient(circle, rgba(255,255,255,0.3) 0%, transparent 70%);
    animation: pulse 3s ease-in-out infinite;
    z-index: -1;
}

/* 边框光效 */
.hero-visual-center::before {
    content: '';
    position: absolute;
    inset: -3px;
    border-radius: 40px;
    padding: 3px;
    background: linear-gradient(135deg, 
        rgba(255,255,255,0.6) 0%, 
        rgba(255,255,255,0.2) 25%,
        rgba(255,255,255,0.6) 50%,
        rgba(255,255,255,0.2) 75%,
        rgba(255,255,255,0.6) 100%
    );
    background-size: 200% 200%;
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    animation: borderGlow 3s linear infinite;
}

@keyframes borderGlow {
    0% {
        background-position: 0% 50%;
    }
    100% {
        background-position: 200% 50%;
    }
}

.hero-visual-center svg {
    width: 80px;
    height: 80px;
    stroke-width: 2;
    filter: drop-shadow(0 6px 12px rgba(0,0,0,0.3));
    animation: iconFloat 4s ease-in-out infinite;
}

@keyframes iconFloat {
    0%, 100% {
        transform: translateY(0) scale(1);
    }
    50% {
        transform: translateY(-8px) scale(1.05);
    }
}

/* 添加粒子效果背景 */
.hero-visual::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(255,255,255,0.1) 1px, transparent 1px),
        radial-gradient(circle at 80% 70%, rgba(255,255,255,0.1) 1px, transparent 1px),
        radial-gradient(circle at 40% 80%, rgba(255,255,255,0.08) 1px, transparent 1px),
        radial-gradient(circle at 90% 20%, rgba(255,255,255,0.08) 1px, transparent 1px);
    background-size: 100px 100px, 120px 120px, 80px 80px, 150px 150px;
    animation: particleFloat 20s linear infinite;
    pointer-events: none;
}

@keyframes particleFloat {
    0% {
        transform: translateY(0);
    }
    100% {
        transform: translateY(-100px);
    }
}

.hero-stats-bar {
    position: relative;
    z-index: 1;
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(20px);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding: 2rem 0;
}

.stats-wrapper {
    display: flex;
    justify-content: space-around;
    align-items: center;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.stat-item svg {
    width: 40px;
    height: 40px;
    opacity: 0.9;
}

.stat-content {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    line-height: 1;
    color: white;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
    color: white;
}

.stat-divider {
    width: 1px;
    height: 50px;
    background: rgba(255, 255, 255, 0.2);
}

/* Section Styles */
.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 20px;
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    color: #92400e;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.section-badge i {
    color: #f59e0b;
}

.section-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
    text-align: center;
    font-weight: 800;
}

.section-subtitle {
    font-size: 1.2rem;
    color: #64748b;
    max-width: 600px;
    margin: 0 auto;
}

/* View All Button in Section Header */
.section-header .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.section-header .btn-primary:active {
    transform: translateY(0);
}

/* Calculator Grid */
.calculator-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.calc-card {
    text-decoration: none;
    color: var(--text-color);
    transition: transform 0.3s;
    position: relative;
}

.calc-card:hover {
    transform: translateY(-8px);
}

.calc-card-inner {
    background: white;
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.calc-card:hover .calc-card-inner {
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.calc-icon {
    width: 80px;
    height: 80px;
    margin-bottom: 1.5rem;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    position: relative;
    overflow: hidden;
}

.gradient-1 {
    background: var(--gradient-1);
}

.gradient-2 {
    background: var(--gradient-2);
}

.gradient-3 {
    background: var(--gradient-3);
}

.gradient-4 {
    background: var(--gradient-4);
}

.calc-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 6px 14px;
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    color: white;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.calc-card h3 {
    font-size: 1.4rem;
    margin-bottom: 0.8rem;
    color: var(--dark-color);
    font-weight: 700;
}

.calc-card p {
    font-size: 1rem;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.calc-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.calc-tag {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: var(--primary-color);
    font-weight: 600;
}

.calc-tag i {
    font-size: 0.9rem;
}

.calc-arrow {
    color: var(--primary-color);
    transition: transform 0.3s;
}

.calc-card:hover .calc-arrow {
    transform: translateX(5px);
}

/* Category Grid */
.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.category-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
}

.category-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.category-header i {
    font-size: 2rem;
    color: var(--primary-color);
}

.category-header h3 {
    font-size: 1.5rem;
    color: var(--dark-color);
}

.category-list {
    list-style: none;
}

.category-list li {
    margin-bottom: 0.8rem;
}

.category-list a {
    text-decoration: none;
    color: var(--text-color);
    transition: color 0.3s, padding-left 0.3s;
    display: block;
}

.category-list a:hover {
    color: var(--primary-color);
    padding-left: 10px;
}

/* Guide Grid */
.guide-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2.5rem;
}

.guide-card.modern {
    background: white;
    border-radius: 24px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.guide-card.modern:hover {
    transform: translateY(-12px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.guide-image-wrapper {
    position: relative;
    overflow: hidden;
}

.guide-image {
    height: 240px;
    overflow: hidden;
    position: relative;
}

.guide-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.guide-card.modern:hover .guide-image img {
    transform: scale(1.15);
}

.guide-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.9) 0%, rgba(139, 92, 246, 0.9) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.4s;
}

.guide-card.modern:hover .guide-overlay {
    opacity: 1;
}

.guide-overlay svg {
    width: 60px;
    height: 60px;
    color: white;
    transform: scale(0.8);
    transition: transform 0.4s;
}

.guide-card.modern:hover .guide-overlay svg {
    transform: scale(1);
}

.guide-category-badge {
    position: absolute;
    top: 20px;
    left: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    z-index: 2;
}

.guide-category-badge svg {
    width: 16px;
    height: 16px;
}

.guide-content {
    padding: 2rem;
}

.guide-meta {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.guide-time {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: #64748b;
}

.guide-time svg {
    width: 16px;
    height: 16px;
}

.guide-level {
    padding: 4px 12px;
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    color: #92400e;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.guide-content h3 {
    font-size: 1.4rem;
    margin-bottom: 0.8rem;
    color: var(--dark-color);
    font-weight: 700;
    line-height: 1.3;
}

.guide-content p {
    margin-bottom: 1.5rem;
    color: #64748b;
    line-height: 1.7;
}

.guide-link {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 700;
    font-size: 1rem;
    transition: gap 0.3s;
}

.guide-link svg {
    width: 18px;
    height: 18px;
}

.guide-link:hover {
    gap: 15px;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1rem;
}

.feature-card {
    text-align: center;
    padding: 2.5rem;
    background: white;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.feature-icon-wrapper {
    margin-bottom: 1.5rem;
}

.feature-icon {
    width: 90px;
    height: 90px;
    margin: 0 auto;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.2rem;
    color: white;
    position: relative;
    animation: pulse 3s ease-in-out infinite;
}

.feature-card h3 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
    font-weight: 700;
}

.feature-card p {
    color: #64748b;
    line-height: 1.7;
}

/* FAQ Section */
.faq-section {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.faq-container {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    margin-bottom: 1.5rem;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.3s;
}

.faq-item:hover {
    box-shadow: var(--shadow-md);
    border-color: rgba(99, 102, 241, 0.2);
}

.faq-question {
    width: 100%;
    padding: 1.8rem 2rem;
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1.5rem;
    transition: background 0.3s;
}

.faq-question:hover {
    background: rgba(99, 102, 241, 0.02);
}

.faq-q-content {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

.faq-icon {
    width: 24px;
    height: 24px;
    color: var(--primary-color);
    flex-shrink: 0;
}

.faq-q-content span {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--dark-color);
}

.faq-chevron {
    width: 24px;
    height: 24px;
    color: var(--primary-color);
    transition: transform 0.3s;
    flex-shrink: 0;
}

.faq-item.active .faq-chevron {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), padding 0.4s;
}

.faq-item.active .faq-answer {
    max-height: 300px;
    padding: 0 2rem 2rem 4.5rem;
}

.faq-answer p {
    color: #64748b;
    line-height: 1.8;
    font-size: 1.05rem;
}

/* Footer */
.footer {
    background: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
    color: white;
}

.footer-top {
    padding: 4rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-cta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 3rem;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2) 0%, rgba(139, 92, 246, 0.2) 100%);
    border-radius: 24px;
    border: 1px solid rgba(99, 102, 241, 0.3);
    backdrop-filter: blur(10px);
}

.footer-cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 800;
}

.footer-cta-content p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.cta-button {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 1.2rem 2.5rem;
    background: white;
    color: var(--primary-color);
    text-decoration: none;
    border-radius: 50px;
    font-weight: 700;
    font-size: 1.1rem;
    transition: all 0.3s;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.cta-button svg {
    width: 20px;
    height: 20px;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.3);
}

.footer-main {
    padding: 4rem 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
}

.footer-brand {
    padding-right: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.8rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
}

.footer-logo svg {
    width: 36px;
    height: 36px;
}

.footer-brand p {
    opacity: 0.8;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.social-links a svg {
    width: 20px;
    height: 20px;
}

.social-links a:hover {
    background: var(--gradient);
    transform: translateY(-3px);
    border-color: transparent;
}

.footer-col h4 {
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-col h4 svg {
    width: 20px;
    height: 20px;
    opacity: 0.8;
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 1rem;
}

.footer-col a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: all 0.3s;
    display: flex;
}

.footer-col a:hover {
    color: white;
    transform: translateX(5px);
}

.footer-bottom {
    padding: 2rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom-content p {
    opacity: 0.7;
    display: flex;
    align-items: center;
    gap: 8px;
}

.heart-icon {
    width: 16px;
    height: 16px;
    color: #ef4444;
    animation: pulse 2s ease-in-out infinite;
}

.footer-links {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: white;
}

.separator {
    opacity: 0.5;
}

/* Mobile Responsive */
@media (max-width: 968px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .hero-right {
        height: 400px;
    }
    
    .hero-stats-bar {
        display: none;
    }
    
    .steps-container {
        grid-template-columns: 1fr;
        gap: 4rem;
    }
    
    .step-line {
        display: none;
    }
    
    .footer-cta {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }
    
    .footer-brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 40px rgba(0,0,0,0.1);
        padding: 2rem 0;
        gap: 0;
        height: calc(100vh - 70px);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        padding: 1.2rem 0;
        border-bottom: 1px solid rgba(99, 102, 241, 0.1);
    }

    .nav-menu li:last-child {
        border-bottom: none;
    }

    .nav-toggle {
        display: flex;
    }

    .hero {
        padding: 60px 0 0;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .hero-search {
        flex-direction: column;
        padding: 12px;
        border-radius: 20px;
    }

    .search-icon {
        display: none;
    }

    .hero-search input {
        padding: 1rem;
        text-align: center;
    }

    .search-btn {
        width: 100%;
        justify-content: center;
        margin-top: 8px;
    }

    .hero-features {
        flex-direction: column;
        gap: 1rem;
    }

    .hero-feature {
        justify-content: center;
    }

    .hero-right {
        height: 300px;
    }

    .floating-card {
        padding: 1.2rem;
    }

    .floating-card svg {
        width: 36px;
        height: 36px;
    }

    .floating-card span {
        font-size: 0.8rem;
    }

    .hero-visual-center {
        width: 100px;
        height: 100px;
    }

    .hero-visual-center svg {
        width: 50px;
        height: 50px;
    }

    .section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .section-subtitle {
        font-size: 1rem;
    }

    .calculator-grid,
    .category-grid,
    .guide-grid,
    .features-grid {
        grid-template-columns: 1fr;
    }

    .calc-card-inner {
        padding: 2rem;
    }

    .calc-badge {
        top: 15px;
        right: 15px;
        font-size: 0.7rem;
        padding: 5px 12px;
    }

    .step-card {
        padding: 3rem 1.5rem 2rem;
    }

    .faq-q-content span {
        font-size: 1rem;
    }

    .faq-item.active .faq-answer {
        padding: 0 1.5rem 1.5rem 3.5rem;
    }

    .footer-cta-content h2 {
        font-size: 1.8rem;
    }

    .footer-cta-content p {
        font-size: 1rem;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }

    .footer-bottom-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .gradient-text {
        display: block;
    }

    .hero-right {
        height: 250px;
    }

    .calc-icon,
    .feature-icon {
        width: 70px;
        height: 70px;
        font-size: 1.8rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .guide-grid {
        grid-template-columns: 1fr;
    }

    .faq-q-content {
        gap: 0.8rem;
    }

    .faq-icon {
        width: 20px;
        height: 20px;
    }

    .faq-q-content span {
        font-size: 0.95rem;
    }

    .faq-item.active .faq-answer {
        padding: 0 1.5rem 1.5rem 1.5rem;
    }

    .footer-cta {
        padding: 2rem 1.5rem;
    }

    .footer-cta-content h2 {
        font-size: 1.5rem;
    }

    .cta-button {
        padding: 1rem 2rem;
        font-size: 1rem;
    }
}

/* How It Works Section */
.how-it-works {
    background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
}

.steps-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 3rem;
    position: relative;
}

.step-card {
    text-align: center;
    padding: 2.5rem 2rem;
    background: white;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.4s;
    position: relative;
}

.step-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.step-number {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.step-number span {
    width: 60px;
    height: 60px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 800;
    color: white;
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
}

.step-line {
    width: 100px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color) 0%, transparent 100%);
    position: absolute;
    left: 60px;
    top: 50%;
}

.step-card:last-child .step-line {
    display: none;
}

.step-icon {
    width: 100px;
    height: 100px;
    margin: 3rem auto 2rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.4s;
}

.step-card:hover .step-icon {
    transform: scale(1.1) rotate(5deg);
}

.step-icon svg {
    width: 50px;
    height: 50px;
    color: white;
}

.step-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
    font-weight: 700;
}

.step-card p {
    color: #64748b;
    line-height: 1.7;
}

/* 连接线动画 */
.connection-lines {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    opacity: 0.4;
}

.connection-lines .line {
    stroke-dasharray: 1000;
    stroke-dashoffset: 1000;
    animation: drawLine 3s ease-out forwards;
}

.line-1 {
    animation-delay: 1s;
}

.line-2 {
    animation-delay: 1.5s;
}

.line-3 {
    animation-delay: 2s;
}

.line-4 {
    animation-delay: 2.5s;
}

@keyframes drawLine {
    to {
        stroke-dashoffset: 0;
    }
}

/* 卡片光晕效果 */
.card-glow {
    position: absolute;
    inset: -20px;
    background: radial-gradient(circle, rgba(255,255,255,0.2) 0%, transparent 70%);
    border-radius: 50%;
    opacity: 0;
    transition: opacity 0.4s;
    pointer-events: none;
}

.floating-card:hover .card-glow {
    opacity: 1;
    animation: glowPulse 2s ease-in-out infinite;
}

@keyframes glowPulse {
    0%, 100% {
        transform: scale(1);
        opacity: 0.5;
    }
    50% {
        transform: scale(1.2);
        opacity: 0.8;
    }
}

/* 中心脉冲效果 */
.center-pulse {
    position: absolute;
    inset: -30px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: centerPulse 3s ease-out infinite;
}

@keyframes centerPulse {
    0% {
        transform: scale(0.8);
        opacity: 1;
    }
    100% {
        transform: scale(1.5);
        opacity: 0;
    }
}

/* 增强移动端响应 */
@media (max-width: 968px) {
    .connection-lines {
        display: none;
    }
    
    .hero-visual-center {
        width: 120px;
        height: 120px;
    }
    
    .hero-visual-center svg {
        width: 60px;
        height: 60px;
    }
}

@media (max-width: 768px) {
    .floating-card {
        padding: 1.5rem 1.2rem;
    }
    
    .floating-card svg {
        width: 40px;
        height: 40px;
    }
    
    .floating-card span {
        font-size: 0.85rem;
    }
    
    .hero-visual-center {
        width: 110px;
        height: 110px;
        border-radius: 30px;
    }
    
    .hero-visual-center svg {
        width: 55px;
        height: 55px;
    }
}

@media (max-width: 480px) {
    .hero-right {
        height: 280px;
    }
    
    .floating-card {
        padding: 1.2rem 1rem;
    }
    
    .floating-card svg {
        width: 32px;
        height: 32px;
    }
    
    .floating-card span {
        font-size: 0.75rem;
    }
    
    .hero-visual-center {
        width: 90px;
        height: 90px;
        border-radius: 25px;
    }
    
    .hero-visual-center svg {
        width: 45px;
        height: 45px;
    }
    
    .card-1 {
        top: 5%;
        left: 2%;
    }
    
    .card-2 {
        top: 8%;
        right: 2%;
    }
    
    .card-3 {
        bottom: 18%;
        left: 0%;
    }
    
    .card-4 {
        bottom: 8%;
        right: 5%;
    }
}

/* ========================================
   How Math Calculators Help Section
   ======================================== */
.calculator-help-section {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    position: relative;
    overflow: hidden;
}

.calculator-help-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--primary-color), transparent);
    opacity: 0.3;
}

.help-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1rem;
    margin-top: 3rem;
}

.help-card {
    background: white;
    border-radius: 20px;
    padding: 1.5rem 1rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.help-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s ease;
}

.help-card:hover::before {
    transform: scaleX(1);
}

.help-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.help-icon {
    width: 70px;
    height: 70px;
    border-radius: 18px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    transition: all 0.4s ease;
}

.help-icon svg {
    width: 36px;
    height: 36px;
    stroke: var(--primary-color);
    transition: all 0.4s ease;
}

.help-card:hover .help-icon {
    background: var(--gradient);
    transform: scale(1.1) rotate(5deg);
}

.help-card:hover .help-icon svg {
    stroke: white;
    transform: scale(1.1);
}

.help-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 1rem;
}

.help-card > p {
    color: var(--text-color);
    line-height: 1.7;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.help-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.help-list li {
    color: var(--text-color);
    padding: 0.6rem 0;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-bottom: 1px solid rgba(0,0,0,0.05);
    transition: all 0.3s ease;
}

.help-list li:last-child {
    border-bottom: none;
}

.help-list li:hover {
    color: var(--primary-color);
    padding-left: 0.5rem;
}

/* ========================================
   Latest Articles Section
   ======================================== */
.latest-articles-section {
    background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
    position: relative;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.article-card {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    display: flex;
    gap: 1.5rem;
}

.article-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.4s ease;
}

.article-card:hover::before {
    transform: scaleY(1);
}

.article-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.article-number {
    font-size: 3rem;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    flex-shrink: 0;
    opacity: 0.3;
    transition: all 0.4s ease;
}

.article-card:hover .article-number {
    opacity: 1;
    transform: scale(1.1);
}

.article-content {
    flex: 1;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.article-date {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.85rem;
    color: #64748b;
}

.article-date svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
}

.article-category {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    color: var(--primary-color);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.article-card:hover .article-category {
    background: var(--gradient);
    color: white;
}

.article-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 0.8rem;
    line-height: 1.4;
    transition: color 0.3s ease;
}

.article-card:hover .article-content h3 {
    color: var(--primary-color);
}

.article-content > p {
    color: var(--text-color);
    line-height: 1.7;
    margin-bottom: 1.2rem;
    font-size: 0.9rem;
}

.article-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
    text-decoration: none;
    transition: all 0.3s ease;
}

.article-link svg {
    width: 18px;
    height: 18px;
    stroke: currentColor;
    transition: transform 0.3s ease;
}

.article-link:hover {
    gap: 0.8rem;
}

.article-link:hover svg {
    transform: translateX(4px);
}

/* ========================================
   More Calculators Section
   ======================================== */
.more-calculators-section {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    position: relative;
}

.more-calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
    margin-top: 3rem;
}

.more-calc-card {
    background: white;
    border-radius: 16px;
    padding: 1.8rem 2rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    gap: 1.5rem;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.more-calc-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.more-calc-card:hover::before {
    opacity: 0.05;
}

.more-calc-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.more-calc-icon {
    width: 60px;
    height: 60px;
    border-radius: 14px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: all 0.4s ease;
    position: relative;
    z-index: 1;
}

.more-calc-icon svg {
    width: 30px;
    height: 30px;
    stroke: var(--primary-color);
    transition: all 0.4s ease;
}

.more-calc-card:hover .more-calc-icon {
    background: var(--gradient);
    transform: scale(1.1) rotate(-5deg);
}

.more-calc-card:hover .more-calc-icon svg {
    stroke: white;
}

.more-calc-content {
    flex: 1;
    position: relative;
    z-index: 1;
}

.more-calc-content h4 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 0.4rem;
    transition: color 0.3s ease;
}

.more-calc-card:hover .more-calc-content h4 {
    color: var(--primary-color);
}

.more-calc-content p {
    color: var(--text-color);
    font-size: 0.9rem;
    line-height: 1.5;
    margin: 0;
}

.more-calc-arrow {
    width: 24px;
    height: 24px;
    stroke: var(--primary-color);
    flex-shrink: 0;
    transition: all 0.4s ease;
    position: relative;
    z-index: 1;
}

.more-calc-card:hover .more-calc-arrow {
    transform: translateX(6px);
    stroke: var(--primary-color);
}

.view-all-btn-wrapper {
    text-align: center;
    margin-top: 3rem;
}

.view-all-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    background: var(--gradient);
    color: white;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.3);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    cursor: pointer;
}

.view-all-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.view-all-btn svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
    transition: transform 0.3s ease;
}

.view-all-btn:hover svg {
    transform: translateX(4px);
}

/* ========================================
   Responsive Design for New Sections
   ======================================== */

/* Tablet */
@media (max-width: 968px) {
    .help-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
    
    .articles-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
    
    .more-calc-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Mobile */
@media (max-width: 768px) {
    .help-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .help-card {
        padding: 2rem 1.5rem;
    }
    
    .help-icon {
        width: 60px;
        height: 60px;
    }
    
    .help-icon svg {
        width: 30px;
        height: 30px;
    }
    
    .help-card h3 {
        font-size: 1.3rem;
    }
    
    .articles-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .article-card {
        padding: 1.5rem;
        flex-direction: column;
        gap: 1rem;
    }
    
    .article-number {
        font-size: 2.5rem;
    }
    
    .more-calc-grid {
        grid-template-columns: 1fr;
    }
    
    .more-calc-card {
        padding: 1.5rem;
    }
    
    .more-calc-icon {
        width: 50px;
        height: 50px;
    }
    
    .more-calc-icon svg {
        width: 26px;
        height: 26px;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .help-card {
        padding: 1.5rem 1.2rem;
    }
    
    .help-card h3 {
        font-size: 1.2rem;
    }
    
    .help-list li {
        font-size: 0.85rem;
    }
    
    .article-card {
        padding: 1.2rem;
    }
    
    .article-number {
        font-size: 2rem;
    }
    
    .article-content h3 {
        font-size: 1.1rem;
    }
    
    .article-content > p {
        font-size: 0.85rem;
    }
    
    .more-calc-card {
        padding: 1.2rem 1.5rem;
        gap: 1rem;
    }
    
    .more-calc-content h4 {
        font-size: 1rem;
    }
    
    .more-calc-content p {
        font-size: 0.85rem;
    }
    
    .view-all-btn {
        padding: 0.9rem 2rem;
        font-size: 0.95rem;
    }
}

/* Section CTA Button */
.section-cta {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    cursor: pointer;
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.15);
}

.btn-outline:hover {
    background: var(--gradient);
    color: white;
    border-color: transparent;
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.4);
}

.btn svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
    transition: transform 0.3s ease;
}

.btn-outline:hover svg {
    transform: translateX(4px);
}

/* Responsive for Section CTA */
@media (max-width: 768px) {
    .section-cta {
        margin-top: 2rem;
    }
    
    .btn {
        padding: 0.9rem 2rem;
        font-size: 0.95rem;
    }
}

/* Modern Calculator Card Styles */
.calc-card.modern {
    background: white;
    border-radius: 24px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    text-decoration: none;
    color: var(--text-color);
}

.calc-card.modern::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.calc-card.modern:hover::before {
    transform: scaleX(1);
}

.calc-card.modern:hover {
    transform: translateY(-12px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.calc-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.5rem;
}

.calc-icon-wrapper {
    width: 70px;
    height: 70px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    transition: transform 0.4s ease;
}

.calc-card.modern:hover .calc-icon-wrapper {
    transform: scale(1.1) rotate(5deg);
}

.calc-icon-wrapper svg {
    width: 32px;
    height: 32px;
    stroke: white;
    position: relative;
    z-index: 2;
}

.calc-badge {
    padding: 0.4rem 0.9rem;
    border-radius: 20px;
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    white-space: nowrap;
}

.calc-badge.popular {
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    color: white;
}

.calc-badge.trending {
    background: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
    color: white;
}

.calc-badge.advanced {
    background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%);
    color: white;
}

.calc-badge.essential {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
}

.calc-card-body {
    flex: 1;
    margin-bottom: 1.5rem;
}

.calc-card-body h3 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 0.7rem;
    line-height: 1.3;
    transition: color 0.3s ease;
}

.calc-card.modern:hover .calc-card-body h3 {
    color: var(--primary-color);
}

.calc-card-body p {
    font-size: 0.95rem;
    color: #64748b;
    line-height: 1.6;
}

.calc-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1.2rem;
    border-top: 1px solid var(--border-color);
}

.calc-card-footer .calc-tag {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--primary-color);
    font-weight: 600;
}

.calc-card-footer .calc-tag svg {
    width: 16px;
    height: 16px;
    stroke: currentColor;
}

.calc-card-footer .calc-arrow {
    width: 20px;
    height: 20px;
    stroke: var(--primary-color);
    transition: transform 0.3s ease;
}

.calc-card.modern:hover .calc-arrow {
    transform: translateX(5px);
}

/* Modern Category Card Styles */
.category-card.modern {
    background: white;
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(99, 102, 241, 0.1);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.category-card.modern::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.category-card.modern:hover::before {
    transform: scaleX(1);
}

.category-card.modern:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(99, 102, 241, 0.3);
}

.category-icon-bg {
    position: absolute;
    top: -50px;
    right: -50px;
    width: 150px;
    height: 150px;
    border-radius: 50%;
    opacity: 0.08;
    transition: all 0.4s ease;
}

.category-card.modern:hover .category-icon-bg {
    transform: scale(1.2);
    opacity: 0.12;
}

.category-card.modern .category-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.8rem;
    padding-bottom: 1.2rem;
    border-bottom: 2px solid var(--border-color);
    position: relative;
}

.category-icon {
    width: 50px;
    height: 50px;
    border-radius: 15px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.category-card.modern:hover .category-icon {
    background: var(--gradient);
    transform: scale(1.1) rotate(5deg);
}

.category-icon svg {
    width: 24px;
    height: 24px;
    stroke: var(--primary-color);
    transition: stroke 0.3s ease;
}

.category-card.modern:hover .category-icon svg {
    stroke: white;
}

.category-card.modern .category-header h3 {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--dark-color);
    margin: 0;
}

.category-card.modern .category-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.category-card.modern .category-list li {
    margin-bottom: 0.9rem;
    position: relative;
    padding-left: 1.5rem;
}

.category-card.modern .category-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--primary-color);
    transition: all 0.3s ease;
}

.category-card.modern .category-list li:hover::before {
    width: 10px;
    background: var(--gradient);
}

.category-card.modern .category-list a {
    text-decoration: none;
    color: var(--text-color);
    font-size: 0.95rem;
    transition: all 0.3s ease;
    display: inline-block;
    position: relative;
}

.category-card.modern .category-list a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: width 0.3s ease;
}

.category-card.modern .category-list a:hover {
    color: var(--primary-color);
    transform: translateX(5px);
}

.category-card.modern .category-list a:hover::after {
    width: 100%;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .calc-card.modern {
        padding: 1.5rem;
    }
    
    .calc-icon-wrapper {
        width: 60px;
        height: 60px;
    }
    
    .calc-icon-wrapper svg {
        width: 28px;
        height: 28px;
    }
    
    .calc-card-body h3 {
        font-size: 1.2rem;
    }
    
    .category-card.modern {
        padding: 2rem;
    }
    
    .category-icon-bg {
        width: 120px;
        height: 120px;
    }
}


/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 1000;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 25px rgba(99, 102, 241, 0.5);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}

@media (max-width: 768px) {
    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 20px;
    }
    
    .back-to-top svg {
        width: 20px;
        height: 20px;
    }
}