/* ===== CSS Variables ===== */
:root {
    --primary-color: #1976d2;
    --primary-light: #42a5f5;
    --background-light: #f7f9fc;
    --text-dark: #263238;
    --white: #ffffff;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-hover: rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

/* ===== Header & Navigation ===== */
.header {
    background: var(--white);
    box-shadow: 0 2px 10px var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo img {
    width: 40px;
    height: 40px;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 3px;
    transition: var(--transition);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: var(--transition);
}

.nav-menu a:hover {
    background: var(--background-light);
    color: var(--primary-color);
}

.nav-cta {
    background: var(--primary-color) !important;
    color: var(--white) !important;
    padding: 0.75rem 1.5rem !important;
    border-radius: 25px !important;
}

.nav-cta:hover {
    background: var(--primary-light) !important;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(25, 118, 210, 0.3);
}

/* ===== Hero Section ===== */
.hero {
    position: relative;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: var(--white);
    padding: 120px 0 180px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="60" height="60" xmlns="http://www.w3.org/2000/svg"><circle cx="30" cy="30" r="2" fill="white" opacity="0.1"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-description {
    font-size: 1.125rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.8s ease 0.6s backwards;
}

.hero-wave {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    overflow: hidden;
    line-height: 0;
}

.hero-wave svg {
    position: relative;
    display: block;
    width: calc(100% + 1.3px);
    height: 80px;
}

.hero-wave path {
    fill: var(--white);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: 500;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background: var(--white);
    color: var(--primary-color);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-secondary:hover {
    background: var(--white);
    color: var(--primary-color);
}

.btn-cta {
    background: var(--white);
    color: var(--primary-color);
    font-size: 1.25rem;
    padding: 1.25rem 3rem;
}

.btn-cta:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

/* ===== Section Styles ===== */
section {
    padding: 80px 0;
}

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

.section-header h2 {
    font-size: 2.5rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.125rem;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Categories Section ===== */
.categories {
    background: var(--white);
}

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

.category-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 4px 15px var(--shadow);
    transition: var(--transition);
    text-align: center;
}

.category-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px var(--shadow-hover);
}

.category-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--white);
}

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

.category-card p {
    color: #666;
    margin-bottom: 1rem;
    line-height: 1.8;
}

.category-count {
    display: inline-block;
    background: var(--background-light);
    color: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

/* ===== Features Section ===== */
.features {
    background: var(--background-light);
}

.features-grid {
    display: grid;
    gap: 2rem;
}

.feature-card {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2rem;
    background: var(--white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 4px 15px var(--shadow);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateX(8px);
    box-shadow: 0 6px 20px var(--shadow-hover);
}

.feature-image {
    border-radius: 10px;
    overflow: hidden;
}

.feature-placeholder {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: var(--white);
}

.feature-content h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.feature-content p {
    color: #666;
    margin-bottom: 1rem;
    line-height: 1.8;
}

.feature-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    list-style: none;
}

.feature-tags li {
    background: var(--background-light);
    color: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
}

/* ===== Testimonials Section ===== */
.testimonials {
    background: var(--white);
}

.testimonials-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.stat-item {
    text-align: center;
    padding: 2rem;
    background: var(--background-light);
    border-radius: 15px;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1rem;
    color: #666;
    margin-bottom: 0.5rem;
}

.stat-stars {
    color: #ffc107;
    font-size: 1.25rem;
}

.testimonials-slider {
    position: relative;
    max-width: 800px;
    margin: 0 auto 2rem;
    min-height: 300px;
}

.testimonial-card {
    display: none;
    background: var(--white);
    padding: 3rem;
    border-radius: 15px;
    box-shadow: 0 4px 20px var(--shadow);
    opacity: 0;
    transition: opacity 0.5s ease;
}

.testimonial-card.active {
    display: block;
    opacity: 1;
}

.testimonial-rating {
    color: #ffc107;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.testimonial-text {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-dark);
    margin-bottom: 2rem;
    font-style: italic;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.author-avatar {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.5rem;
}

.author-name {
    font-weight: 600;
    font-size: 1.125rem;
    color: var(--text-dark);
}

.author-meta {
    font-size: 0.875rem;
    color: #999;
}

.testimonials-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
}

.testimonial-prev,
.testimonial-next {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-color);
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: var(--transition);
}

.testimonial-prev:hover,
.testimonial-next:hover {
    background: var(--primary-light);
    transform: scale(1.1);
}

.testimonials-dots {
    display: flex;
    gap: 0.75rem;
}

.testimonial-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #ddd;
    cursor: pointer;
    transition: var(--transition);
}

.testimonial-dot.active {
    background: var(--primary-color);
    width: 30px;
    border-radius: 6px;
}

/* ===== FAQ Section ===== */
.faq {
    background: var(--background-light);
}

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

.faq-item {
    background: var(--white);
    margin-bottom: 1rem;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px var(--shadow);
}

.faq-question {
    width: 100%;
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-dark);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.faq-question:hover {
    background: var(--background-light);
    color: var(--primary-color);
}

.faq-question i {
    transition: transform 0.3s ease;
    color: var(--primary-color);
}

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

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 2rem 1.5rem;
}

.faq-answer p {
    color: #666;
    line-height: 1.8;
}

/* ===== CTA Section ===== */
.cta {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: var(--white);
    text-align: center;
    padding: 100px 0;
}

.cta-content h2 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.cta-content p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

/* ===== Footer ===== */
.footer {
    background: var(--text-dark);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h3 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--white);
}

.footer-col p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
}

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

.footer-col ul li {
    margin-bottom: 0.75rem;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.7);
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: var(--primary-light);
    padding-left: 5px;
}

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

.social-links a {
    width: 45px;
    height: 45px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary-light);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

.footer-disclaimer {
    font-size: 0.875rem;
    opacity: 0.8;
}

/* ===== Back to Top Button ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 50%;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.visible {
    display: flex;
}

.back-to-top:hover {
    background: var(--primary-light);
    transform: translateY(-5px);
}

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

/* ===== Responsive Design ===== */
@media (max-width: 968px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 2rem;
        box-shadow: 0 4px 10px var(--shadow);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-20px);
        transition: var(--transition);
    }

    .nav-menu.active {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

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

    .hero-subtitle {
        font-size: 1.125rem;
    }

    .feature-card {
        grid-template-columns: 1fr;
    }

    .feature-placeholder {
        height: 150px;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .cta-content h2 {
        font-size: 2rem;
    }
}

@media (max-width: 640px) {
    .hero {
        padding: 80px 0 140px;
    }

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

    .hero-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }

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

    .testimonial-card {
        padding: 2rem 1.5rem;
    }

    .testimonial-text {
        font-size: 1rem;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}