:root {
    --bg-color: #000000;
    --text-color: #f5f5f7;
    --text-secondary: #86868b;
    --accent-color: #2997ff;
    --accent-hover: #0071e3;
    --card-bg: #1d1d1f;
    --nav-bg: rgba(0, 0, 0, 0.8);
    --font-main: "SF Pro Display", "SF Pro Icons", "Helvetica Neue", "Helvetica", "Arial", sans-serif;
    --max-width: 980px;
    --transition: all 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    line-height: 1.47059;
    font-weight: 400;
    letter-spacing: -0.022em;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 600;
    letter-spacing: -0.003em;
}

.section-title {
    font-size: 48px;
    line-height: 1.08349;
    font-weight: 600;
    letter-spacing: -0.003em;
    margin-bottom: 20px;
    text-align: center;
}

.section-subtitle {
    font-size: 24px;
    line-height: 1.16667;
    font-weight: 400;
    letter-spacing: 0.009em;
    color: var(--text-secondary);
    text-align: center;
    max-width: 600px;
    margin: 0 auto 60px;
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 48px;
    background: var(--nav-bg);
    backdrop-filter: saturate(180%) blur(20px);
    z-index: 9999;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-color);
}

.nav-links {
    display: flex;
    gap: 24px;
}

.nav-link {
    font-size: 12px;
    color: #e8e8ed;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.nav-link:hover {
    opacity: 1;
}

.cta-button-small {
    background: var(--accent-color);
    color: white;
    padding: 4px 12px;
    border-radius: 980px;
    font-size: 12px;
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding-top: 48px;
    position: relative;
    overflow: hidden;
}

.hero-content {
    z-index: 2;
    max-width: 800px;
}

.hero-new {
    color: #f56300;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 10px;
    display: block;
}

.hero-title {
    font-size: 80px;
    line-height: 1.05;
    font-weight: 600;
    letter-spacing: -0.015em;
    margin-bottom: 10px;
    background: linear-gradient(180deg, #fff 0%, #aaa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 28px;
    line-height: 1.14286;
    font-weight: 400;
    letter-spacing: 0.007em;
    margin-bottom: 30px;
}

.hero-cta-group {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-top: 20px;
}

.btn-primary {
    background: var(--accent-color);
    color: white;
    padding: 12px 24px;
    border-radius: 980px;
    font-size: 17px;
    font-weight: 400;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary:hover {
    background: var(--accent-hover);
}

.btn-secondary {
    color: var(--accent-color);
    font-size: 17px;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.btn-secondary:hover {
    text-decoration: underline;
}

.hero-video-container {
    margin-top: 60px;
    width: 100%;
    max-width: 1000px;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
    opacity: 0;
    transform: translateY(50px);
    animation: fadeUp 1s 0.5s forwards;
}

.hero-video-element {
    width: 100%;
    display: block;
}

/* Bento Grid for Problems */
.problems {
    padding: 150px 0;
    background: #000;
}

.bento-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 60px;
}

.bento-card {
    background: var(--card-bg);
    border-radius: 30px;
    padding: 40px;
    overflow: hidden;
    position: relative;
    transition: transform 0.3s ease;
}

.bento-card:hover {
    transform: scale(1.02);
}

.bento-card.large {
    grid-column: span 2;
}

.card-icon {
    font-size: 40px;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #ff3b30, #ff9500);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.card-title {
    font-size: 32px;
    margin-bottom: 15px;
}

.card-text {
    font-size: 19px;
    color: var(--text-secondary);
    line-height: 1.4;
}

/* Features / Solutions */
.features {
    padding: 150px 0;
    background: #111;
}

.feature-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 120px;
}

.feature-row.reverse {
    flex-direction: row-reverse;
}

.feature-text-content {
    flex: 1;
    padding: 0 40px;
}

.feature-visual {
    flex: 1;
    height: 400px;
    background: #222;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.feature-title {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-desc {
    font-size: 21px;
    color: var(--text-secondary);
}

/* Stats Section */
.stats-section {
    padding: 100px 0;
    text-align: center;
    background: #000;
}

.big-stat {
    font-size: 120px;
    font-weight: 700;
    line-height: 1;
    background: linear-gradient(90deg, #2997ff, #bf5af2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    font-size: 24px;
    color: var(--text-secondary);
    margin-top: 10px;
}

/* Pricing */
.pricing {
    padding: 150px 0;
    text-align: center;
}

.pricing-card {
    background: var(--card-bg);
    border-radius: 30px;
    padding: 60px;
    max-width: 600px;
    margin: 0 auto;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.price-tag {
    font-size: 80px;
    font-weight: 700;
    margin: 20px 0;
}

.price-period {
    font-size: 20px;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    background: #111;
    padding: 60px 0;
    font-size: 12px;
    color: var(--text-secondary);
    border-top: 1px solid #333;
}

.footer-links {
    display: flex;
    gap: 20px;
    margin-top: 20px;
}

/* Animations */
@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-section {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 1s ease-out, transform 1s ease-out;
}

.fade-in-section.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Utilities */
.icon-sm {
    font-size: 16px;
}

.icon-gradient-gray {
    background: linear-gradient(135deg, #8e8e93, #636366);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.bg-gradient-dark {
    background: linear-gradient(135deg, #1c1c1e, #2c2c2e);
}

.text-center {
    text-align: center;
}

.p-0 {
    padding: 0;
}

.img-cover {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.unit-lg {
    font-size: 40px;
}

.mt-60 {
    margin-top: 60px;
}

.bg-black {
    background: #000;
}

.bg-none {
    background: none;
}

.teacher-img {
    width: 300px;
    border-radius: 50%;
}

.accent-bold {
    color: var(--accent-color);
    font-weight: 600;
}

.bg-dark-gray {
    background: #111;
}

.list-secondary {
    color: var(--text-secondary);
    line-height: 1.6;
}

.price-note {
    color: var(--text-secondary);
    margin-bottom: 40px;
    font-size: 14px;
}

.btn-lg-full {
    width: 100%;
    justify-content: center;
    padding: 20px;
    font-size: 20px;
}

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

/* Mobile Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 48px;
    }

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

    .bento-card.large {
        grid-column: span 1;
    }

    .feature-row {
        flex-direction: column;
        text-align: center;
        gap: 40px;
    }

    .feature-row.reverse {
        flex-direction: column;
    }
}