* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --primary: #E87D0D;
    --primary-light: #FF9A3C;
    --primary-dark: #C66A0A;
    --bg-white: #FFFFFF;
    --bg-light: #F8F9FA;
    --bg-gray: #F1F3F5;
    --text-dark: #1A1A2E;
    --text-gray: #6B7280;
    --text-light: #9CA3AF;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
    --shadow-lg: 0 20px 60px rgba(0,0,0,0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
}

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-white);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Loader */
.loader {
    position: fixed;
    inset: 0;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s, visibility 0.5s;
}
.loader.hidden { opacity: 0; visibility: hidden; }
.loader-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid var(--bg-gray);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 2rem;
    transition: all 0.3s ease;
}
.nav.scrolled {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-sm);
}
.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--text-dark);
    text-decoration: none;
}
.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
}
.nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}
.nav-links a {
    color: var(--text-gray);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s;
    position: relative;
}
.nav-links a:hover, .nav-links a.active { color: var(--primary); }
.nav-links a.active::after { width: 100%; }
.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s;
}
.nav-links a:hover::after { width: 100%; }
.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 0.5rem;
}
.mobile-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-dark);
    transition: all 0.3s;
}

/* Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}
#three-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}
.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    padding: 2rem;
}
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(232, 125, 13, 0.1);
    color: var(--primary);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
}
.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--text-dark), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero p {
    font-size: 1.25rem;
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto 2.5rem;
}
.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    padding: 1rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}
.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    box-shadow: 0 10px 30px rgba(232, 125, 13, 0.3);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 40px rgba(232, 125, 13, 0.4);
}
.btn-secondary {
    background: var(--bg-light);
    color: var(--text-dark);
}
.btn-secondary:hover {
    background: var(--bg-gray);
    transform: translateY(-2px);
}

/* Sections */
section { padding: 6rem 2rem; }
.container { max-width: 1400px; margin: 0 auto; }
.section-header { text-align: center; margin-bottom: 4rem; }
.section-tag {
    display: inline-block;
    color: var(--primary);
    font-weight: 600;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 1rem;
}
.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: 1rem;
}
.section-desc {
    color: var(--text-gray);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Shortcuts */
#shortcuts { background: var(--bg-light); }
.search-box {
    max-width: 400px;
    margin: 0 auto 2rem;
    position: relative;
}
.search-box input {
    width: 100%;
    padding: 1rem 1.5rem 1rem 3rem;
    border: 2px solid var(--bg-gray);
    border-radius: 50px;
    font-size: 1rem;
    transition: all 0.3s;
    background: white;
}
.search-box input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 5px 30px rgba(232, 125, 13, 0.15);
}
.search-box i {
    position: absolute;
    left: 1.25rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-light);
}
.shortcuts-filter {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}
.filter-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    background: white;
    border-radius: 50px;
    font-weight: 500;
    color: var(--text-gray);
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.9rem;
}
.filter-btn:hover, .filter-btn.active {
    background: var(--primary);
    color: white;
    box-shadow: 0 5px 20px rgba(232, 125, 13, 0.3);
}
.shortcuts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}
.shortcut-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    cursor: pointer;
    border: 1px solid rgba(0,0,0,0.04);
}
.shortcut-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-lg);
}
.shortcut-card:hover .key {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    transform: scale(1.1);
    border-color: var(--primary);
    box-shadow: 0 4px 0 var(--primary-dark), 0 6px 12px rgba(232, 125, 13, 0.3);
}
.shortcut-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 0.75rem;
}
.keys {
    display: flex;
    gap: 0.4rem;
    align-items: center;
    flex-wrap: wrap;
}
.key {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 42px;
    height: 42px;
    padding: 0 12px;
    background: linear-gradient(180deg, #f8f9fa 0%, #e9ecef 100%);
    border: 1px solid #dee2e6;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--text-dark);
    box-shadow: 0 3px 0 #d1d5db, 0 4px 8px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    font-family: 'SF Mono', 'Consolas', monospace;
}
.key-plus {
    color: var(--text-light);
    font-weight: 400;
    font-size: 1rem;
    margin: 0 2px;
}
.shortcut-info { flex: 1; }
.shortcut-title {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--text-dark);
    margin-bottom: 0.25rem;
}
.shortcut-desc {
    color: var(--text-gray);
    font-size: 0.875rem;
    line-height: 1.5;
}
.shortcut-category {
    display: inline-block;
    margin-top: 0.75rem;
    padding: 0.25rem 0.75rem;
    background: var(--bg-light);
    border-radius: 50px;
    font-size: 0.7rem;
    color: var(--text-gray);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Tutorials */
.tutorials-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}
.tab-btn {
    padding: 1rem 2rem;
    border: none;
    background: white;
    border-radius: var(--radius-md);
    font-weight: 600;
    color: var(--text-gray);
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: var(--shadow-sm);
}
.tab-btn:hover, .tab-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    box-shadow: 0 10px 30px rgba(232, 125, 13, 0.3);
}
.tab-btn i { margin-right: 0.5rem; }
.tutorials-content { display: none; }
.tutorials-content.active {
    display: block;
    animation: fadeIn 0.5s ease;
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
.tutorial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}
.tutorial-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all 0.4s ease;
    border: 1px solid rgba(0,0,0,0.04);
}
.tutorial-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}
.tutorial-image {
    height: 180px;
    background: linear-gradient(135deg, var(--bg-gray), var(--bg-light));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    position: relative;
}
.tutorial-image::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(232, 125, 13, 0.08), transparent);
}
.tutorial-body { padding: 1.5rem; }
.tutorial-level {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}
.level-beginner { background: #D1FAE5; color: #065F46; }
.level-intermediate { background: #FEF3C7; color: #92400E; }
.level-advanced { background: #FEE2E2; color: #991B1B; }
.tutorial-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}
.tutorial-desc {
    color: var(--text-gray);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    line-height: 1.6;
}
.tutorial-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
    transition: gap 0.3s;
}
.tutorial-link:hover { gap: 0.75rem; }

/* Resources */
#resources { background: var(--bg-light); }
.resources-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}
.resource-category {
    background: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}
.resource-category:hover { box-shadow: var(--shadow-md); transform: translateY(-4px); }
.resource-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, rgba(232, 125, 13, 0.1), rgba(255, 154, 60, 0.1));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
}
.resource-category h3 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}
.resource-list { list-style: none; }
.resource-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--bg-gray);
}
.resource-list li:last-child { border-bottom: none; }
.resource-list a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    font-size: 0.95rem;
}
.resource-list a:hover {
    color: var(--primary);
    padding-left: 0.5rem;
}
.resource-list a i {
    color: var(--text-light);
    transition: all 0.3s;
    font-size: 0.8rem;
}
.resource-list a:hover i {
    color: var(--primary);
    transform: translateX(4px);
}
.resource-tag {
    font-size: 0.65rem;
    padding: 0.15rem 0.5rem;
    background: var(--bg-light);
    border-radius: 50px;
    color: var(--text-gray);
    margin-left: 0.5rem;
    font-weight: 500;
}

/* Footer */
footer {
    background: var(--text-dark);
    color: white;
    padding: 4rem 2rem 2rem;
}
.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}
.footer-brand h3 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
}
.footer-brand p {
    color: rgba(255,255,255,0.6);
    line-height: 1.8;
    font-size: 0.9rem;
}
.footer-links h4 {
    margin-bottom: 1.25rem;
    font-size: 1rem;
}
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 0.6rem; }
.footer-links a {
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    transition: all 0.3s;
    font-size: 0.9rem;
}
.footer-links a:hover { color: var(--primary); }
.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.4);
    font-size: 0.85rem;
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    box-shadow: 0 5px 20px rgba(232, 125, 13, 0.4);
    z-index: 100;
}
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { transform: translateY(-4px); }

/* Reveal Animation */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.8s cubic-bezier(0.5, 0, 0, 1);
}
.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem 2rem;
        gap: 1rem;
        box-shadow: var(--shadow-md);
    }
    .nav-links.active { display: flex; }
    .mobile-toggle { display: flex; }
    .shortcuts-grid { grid-template-columns: 1fr; }
    .tutorial-grid { grid-template-columns: 1fr; }
    .tutorials-tabs { flex-wrap: wrap; }
    .tab-btn { padding: 0.75rem 1.25rem; font-size: 0.875rem; }
    section { padding: 4rem 1rem; }
    .hero h1 { font-size: 2.5rem; }
}