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

:root {
    --bg: #ffffff;
    --bg-alt: #faf8f5;
    --panel: #ffffff;
    --panel-border: #e8e4df;
    --text: #1a1a1a;
    --muted: #666666;
    --accent: #1a1a1a;
    --accent-2: #333333;
    --link-color: #0071e3;
    --success-color: #28a745;
    --error-color: #ff3b30;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    background: var(--bg);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    text-decoration: none;
    transition: color 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.logo a:hover {
    opacity: 0.7;
}

.logo-icon {
    width: 1.3rem;
    height: 1.3rem;
    flex-shrink: 0;
}

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

.nav-menu a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    opacity: 0.6;
}

.nav-cta {
    background: var(--accent);
    color: #fff !important;
    padding: 0.5rem 1.25rem;
    border-radius: 980px;
    transition: all 0.3s ease;
    font-weight: 600;
}

.nav-cta:hover {
    background: var(--accent-2);
    transform: translateY(-1px);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text);
    transition: all 0.3s ease;
    border-radius: 2px;
}

/* Hero Section */
.hero {
    margin-top: 70px;
    padding: 80px 0 100px;
    min-height: calc(100vh - 70px);
    display: flex;
    align-items: center;
}

.hero-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 4rem;
    align-items: center;
}

.hero-text {
    z-index: 1;
}

.hero-rating {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.stars {
    color: #fbbf24;
    font-size: 1rem;
    letter-spacing: 2px;
}

.rating-text {
    color: var(--muted);
    font-size: 0.9rem;
    font-weight: 500;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.1;
    color: var(--text);
    letter-spacing: -1.5px;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    color: var(--muted);
    font-weight: 400;
    line-height: 1.6;
}

.btn-large {
    padding: 18px 40px;
    font-size: 1.125rem;
    font-weight: 600;
}

/* Phone Mockups */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    perspective: 1000px;
}

.phone-mockup {
    width: 200px;
    height: 400px;
    background: #1d1d1f;
    border-radius: 24px;
    padding: 8px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.18);
    border: 1px solid #3a3a3c;
    position: relative;
}

.phone-left {
    transform: rotateY(-5deg) rotateX(5deg);
    z-index: 1;
}

.phone-right {
    transform: rotateY(5deg) rotateX(-5deg);
    z-index: 2;
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: #000000;
    border-radius: 16px;
    overflow: hidden;
    position: relative;
}

.phone-header {
    padding: 12px 16px;
    text-align: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: #98989d;
    border-bottom: 1px solid #2c2c2e;
}

.phone-content {
    padding: 16px;
    height: calc(100% - 45px);
    overflow-y: auto;
}

.app-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #f5f5f7;
}

.mind-map {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.mind-node {
    padding: 0.75rem 1rem;
    border-radius: 8px;
    color: white;
    font-size: 0.85rem;
    font-weight: 600;
    text-align: center;
}

/* Player Styles */
.player {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.player-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.tab {
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 500;
    color: #98989d;
    cursor: pointer;
}

.tab.active {
    background: var(--accent);
    color: #fff;
}

.player-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    color: white;
}

.player-icon {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.player-title {
    font-size: 1.125rem;
    font-weight: 700;
}

.player-info {
    font-size: 0.75rem;
    color: #98989d;
    text-align: center;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.player-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
}

.control-btn {
    background: #2c2c2e;
    border: 1px solid #3a3a3c;
    color: #f5f5f7;
    padding: 0.75rem;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.play-btn {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    width: 56px;
    height: 56px;
}

.control-btn:hover {
    transform: scale(1.1);
}

.player-progress {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.progress-bar {
    flex: 1;
    height: 4px;
    background: #3a3a3c;
    border-radius: 2px;
    position: relative;
    overflow: hidden;
}

.progress-bar::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 30%;
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
}

.progress-time {
    font-size: 0.75rem;
    color: #98989d;
    font-weight: 600;
}

.player-options {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    font-size: 0.875rem;
    color: #98989d;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 14px 28px;
    border-radius: 980px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 1px solid var(--panel-border);
    cursor: pointer;
    font-size: 1rem;
    font-family: inherit;
    background: var(--bg-alt);
    color: var(--text);
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    border-radius: 980px;
    box-shadow: none;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.2);
    background: var(--accent-2);
}

.btn-secondary {
    background: transparent;
    color: var(--text);
    border: 2px solid var(--panel-border);
}

.btn-secondary:hover {
    background: var(--text);
    color: #fff;
    transform: translateY(-2px);
}

.btn-block {
    width: 100%;
    text-align: center;
}

/* Section Headers */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    color: var(--text);
    letter-spacing: -1px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--muted);
    font-weight: 400;
}

/* Benefits Section */
.benefits {
    padding: 100px 0;
    background: var(--bg-alt);
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.benefit-card {
    background: var(--panel);
    padding: 2.5rem;
    border-radius: 20px;
    transition: all 0.3s ease;
    border: none;
    box-shadow: var(--shadow-sm);
}

.benefit-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent);
    box-shadow: var(--shadow-lg);
}

.benefit-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    display: block;
}

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

.benefit-card p {
    color: var(--muted);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.benefit-list {
    list-style: none;
    margin-top: 1.5rem;
}

.benefit-list li {
    padding: 0.5rem 0;
    color: var(--text);
    font-size: 0.95rem;
}

.achievement-stats {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--panel-border);
}

.achievement {
    padding: 1rem;
    background: var(--bg-alt);
    border-radius: 12px;
    margin-bottom: 0.75rem;
    text-align: center;
    border: 1px solid var(--panel-border);
}

.achievement strong {
    color: var(--text);
    font-size: 1.125rem;
}

/* Learning Plans Section */
.learning-plans {
    padding: 100px 0;
}

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

.plan-card {
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.plan-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--panel-border);
}

.plan-blue {
    background: var(--panel);
    border: 1px solid var(--panel-border);
}

.plan-pink {
    background: var(--panel);
    border: 1px solid var(--panel-border);
}

.plan-green {
    background: var(--panel);
    border: 1px solid var(--panel-border);
}

.plan-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.plan-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.plan-title {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--muted);
    margin-bottom: 0.5rem;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.plan-subtitle {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text);
    margin-bottom: 1.5rem;
}

.plan-features {
    list-style: none;
    margin-bottom: 2rem;
}

.plan-features li {
    padding: 0.75rem 0;
    color: var(--text);
    font-weight: 500;
    border-bottom: 1px solid var(--panel-border);
}

.plan-features li:last-child {
    border-bottom: none;
}

.btn-plan {
    width: 100%;
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    border-radius: 980px;
    text-align: center;
    padding: 14px 28px;
}

.btn-plan:hover {
    background: var(--accent-2);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
}

/* How It Works Section */
.how-it-works {
    padding: 100px 0;
    background: var(--bg-alt);
}

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

.step {
    text-align: center;
}

.step-number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    font-weight: 900;
    margin: 0 auto 1.5rem;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.12);
}

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

.step p {
    color: var(--muted);
    line-height: 1.7;
}

/* Topics Section */
.topics {
    padding: 100px 0;
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.topic-card {
    border-radius: 16px;
    padding: 2rem;
    display: flex;
    align-items: flex-start;
    background: var(--panel);
    border: 1px solid var(--panel-border);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.topic-card::before {
    display: none;
}

.topic-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: #ccc;
}

.topic-content {
    position: relative;
    z-index: 1;
}

.card-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 1rem;
}

.topic-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.topic-card p {
    font-size: 0.95rem;
    color: var(--muted);
    line-height: 1.6;
}

.topic-card.category-card {
    text-decoration: none;
    color: inherit;
}

.category-cta {
    display: inline-block;
    margin-top: 0.75rem;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text);
}

.topic-card.category-card:hover .category-cta {
    text-decoration: underline;
}

/* Contact Section */
.contact {
    padding: 100px 0;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 4rem;
    margin-top: 3rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.contact-item {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
}

.contact-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.contact-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text);
    font-weight: 600;
}

.contact-item p {
    color: var(--muted);
    line-height: 1.8;
}

/* Contact Form */
.contact-form {
    background: var(--bg-alt);
    padding: 3rem;
    border-radius: 20px;
    border: none;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text);
    font-size: 0.95rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    border: 1px solid var(--panel-border);
    border-radius: 10px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
    background: var(--bg);
    color: var(--text);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--text);
    box-shadow: 0 0 0 3px rgba(26, 26, 26, 0.08);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
    font-weight: 500;
    display: none;
}

.form-message.success {
    display: block;
    background: rgba(40, 167, 69, 0.08);
    color: var(--success-color);
    border: 1px solid rgba(40, 167, 69, 0.2);
}

.form-message.error {
    display: block;
    background: rgba(255, 59, 48, 0.08);
    color: var(--error-color);
    border: 1px solid rgba(255, 59, 48, 0.2);
}

/* Footer */
.footer {
    background: var(--bg-alt);
    border-top: 1px solid var(--panel-border);
    color: var(--text);
    padding: 60px 0 20px;
}

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

.footer-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    font-weight: 800;
    color: var(--text);
}

.footer-section h4 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.footer-section p {
    color: var(--muted);
    line-height: 1.8;
}

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

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

.footer-section a {
    color: var(--muted);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--text);
}

.social-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--panel-border);
    color: var(--muted);
}

/* Responsive Design */
@media (max-width: 968px) {
    .hero-wrapper {
        grid-template-columns: 1fr;
        gap: 3rem;
    }

    .hero-visual {
        order: -1;
        margin-bottom: 2rem;
    }

    .phone-mockup {
        width: 160px;
        height: 320px;
    }

    .benefits-grid,
    .plans-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background: rgba(250, 248, 245, 0.98);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        width: 100%;
        padding: 2rem;
        border-bottom: 1px solid var(--panel-border);
        transition: left 0.3s ease;
        gap: 1rem;
        align-items: flex-start;
    }

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

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

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

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero {
        padding: 40px 0 60px;
        min-height: auto;
    }

    .hero-title {
        font-size: 2.25rem;
        letter-spacing: -1px;
    }

    .hero-subtitle {
        font-size: 1.05rem;
    }

    .section-header h2 {
        font-size: 1.75rem;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

    .steps-container {
        grid-template-columns: 1fr;
    }

    .benefits, .learning-plans, .how-it-works, .topics, .contact {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 1.85rem;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .phone-mockup {
        width: 130px;
        height: 260px;
    }

    .contact-form {
        padding: 1.5rem;
    }

    .benefit-card {
        padding: 1.5rem;
    }

    .plan-card {
        padding: 1.5rem;
    }
}