/* SudoLearn Landing Page */
/* Color Palette: Dark terminal aesthetic with green accents */

:root {
    --bg: #0d1117;
    --bg-card: #161b22;
    --bg-dark: #010409;
    --text: #e6edf3;
    --text-muted: #8b949e;
    --green: #3fb950;
    --green-dim: #238636;
    --blue: #58a6ff;
    --orange: #f0883e;
    --red: #f85149;
    --yellow: #d29922;
    --border: #30363d;
    --radius: 12px;
    --font: 'Inter', -apple-system, sans-serif;
    --mono: 'JetBrains Mono', 'Fira Code', monospace;
}

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

html { scroll-behavior: smooth; }

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.center { text-align: center; }

/* Nav */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(13, 17, 23, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
}

.nav-inner {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-family: var(--mono);
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--green);
}

.logo-prompt {
    color: var(--text-muted);
    margin-right: 4px;
}

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

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.nav-links a:hover { color: var(--text); }

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.btn-sm { padding: 8px 16px; font-size: 0.85rem; }
.btn-lg { padding: 16px 32px; font-size: 1.1rem; }

.btn-primary {
    background: var(--green);
    color: var(--bg);
}
.btn-primary:hover { background: #4ae05e; transform: translateY(-1px); }

.btn-outline {
    background: transparent;
    color: var(--green);
    border: 2px solid var(--green);
}
.btn-outline:hover { background: var(--green); color: var(--bg); }

/* Hero */
.hero {
    padding: 160px 24px 100px;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.terminal-badge {
    display: inline-block;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 8px 20px;
    margin-bottom: 32px;
    font-family: var(--mono);
    font-size: 0.9rem;
}

.terminal-text { color: var(--green); }

.cursor {
    color: var(--green);
    animation: blink 1s step-end infinite;
}

@keyframes blink {
    50% { opacity: 0; }
}

.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 24px;
}

.highlight { color: var(--green); }

.hero-sub {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-note {
    margin-top: 16px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Sections */
.section {
    padding: 100px 24px;
}

.section-dark {
    background: var(--bg-dark);
}

.section h2 {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 800;
    margin-bottom: 16px;
    text-align: center;
}

.section-sub {
    color: var(--text-muted);
    text-align: center;
    max-width: 600px;
    margin: 0 auto 48px;
    font-size: 1.1rem;
}

/* Comparison Cards */
.comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-top: 48px;
}

.comp-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
}

.comp-card h3 { margin-bottom: 16px; font-size: 1.2rem; }
.comp-card ul { list-style: none; }
.comp-card li { padding: 8px 0; color: var(--text-muted); }
.comp-good { border-color: var(--green-dim); }
.comp-good li { color: var(--text); }
.comp-good strong { color: var(--green); }
.comp-bad li { text-decoration: line-through; opacity: 0.7; }

/* Steps */
.steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    margin-top: 48px;
}

.step { text-align: center; }

.step-num {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--green-dim);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    margin: 0 auto 16px;
}

.step h3 { margin-bottom: 8px; }
.step p { color: var(--text-muted); font-size: 0.9rem; }
.step code {
    background: var(--bg-dark);
    padding: 2px 8px;
    border-radius: 4px;
    font-family: var(--mono);
    font-size: 0.85rem;
    color: var(--green);
}

/* Terminal Window */
.terminal-window {
    background: #1a1a2e;
    border-radius: var(--radius);
    overflow: hidden;
    max-width: 700px;
    margin: 48px auto 0;
    border: 1px solid var(--border);
}

.terminal-header {
    background: #2d2d44;
    padding: 12px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.terminal-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}
.terminal-dot.red { background: #ff5f57; }
.terminal-dot.yellow { background: #febc2e; }
.terminal-dot.green { background: #28c840; }
.terminal-title {
    margin-left: 12px;
    font-family: var(--mono);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.terminal-body {
    padding: 24px;
    font-family: var(--mono);
    font-size: 0.8rem;
    line-height: 1.6;
    color: #c9d1d9;
    overflow-x: auto;
}

.t-green { color: var(--green); }
.t-blue { color: var(--blue); }

/* Lab Grid */
.lab-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 48px;
}

.lab-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    text-align: center;
    transition: transform 0.2s, border-color 0.2s;
    position: relative;
}

.lab-card:hover {
    transform: translateY(-4px);
    border-color: var(--green-dim);
}

.lab-card.free { border-color: var(--green); }

.lab-badge {
    position: absolute;
    top: 12px;
    right: 12px;
    background: var(--green);
    color: var(--bg);
    font-size: 0.7rem;
    font-weight: 700;
    padding: 4px 8px;
    border-radius: 4px;
}

/* Lab Stats */
.lab-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin: 48px 0 32px;
}

.stat {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 16px;
}

.stat-num {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--green);
    font-family: var(--mono);
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 8px;
}

.lab-note {
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
    font-size: 1rem;
    line-height: 1.7;
}

/* Lab Grid (removed - replaced by stats) */
.lab-card h3 { font-size: 1rem; margin-bottom: 4px; }
.lab-card p { color: var(--text-muted); font-size: 0.85rem; font-family: var(--mono); }

/* Skills Grid */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-top: 48px;
}

.skill {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    text-align: center;
    font-size: 0.9rem;
    font-weight: 600;
}

/* Pricing */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 48px;
}

.price-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 40px 32px;
    text-align: center;
    position: relative;
}

.price-card.featured {
    border-color: var(--green);
    transform: scale(1.05);
}

.popular-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--green);
    color: var(--bg);
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 12px;
}

.price-card h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
}

.price {
    font-size: 3rem;
    font-weight: 900;
    color: var(--green);
    margin-bottom: 8px;
}

.price span {
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-muted);
}

.price-desc {
    color: var(--text-muted);
    margin-bottom: 24px;
}

.price-card ul {
    list-style: none;
    text-align: left;
    margin-bottom: 32px;
}

.price-card li {
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.9rem;
}

.price-card li:last-child { border: none; }

.price-card .btn { width: 100%; }

.pricing-compare {
    text-align: center;
    margin-top: 32px;
    color: var(--text-muted);
    font-style: italic;
}

/* Testimonial */
.testimonial {
    font-size: 1.3rem;
    font-style: italic;
    color: var(--text);
    max-width: 700px;
    margin: 0 auto 16px;
    line-height: 1.7;
    border-left: 4px solid var(--green);
    padding-left: 24px;
    text-align: left;
}

.testimonial-author {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* CTA Section */
.section-cta {
    background: linear-gradient(135deg, var(--bg-dark), #0a1628);
    border-top: 1px solid var(--border);
}

.section-cta h2 { margin-bottom: 16px; }
.section-cta p { color: var(--text-muted); margin-bottom: 32px; }

.cta-form {
    display: flex;
    gap: 12px;
    justify-content: center;
    max-width: 500px;
    margin: 0 auto;
}

.cta-form input {
    flex: 1;
    padding: 16px 20px;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text);
    font-size: 1rem;
    font-family: var(--font);
}

.cta-form input:focus {
    outline: none;
    border-color: var(--green);
}

/* Footer */
.footer {
    border-top: 1px solid var(--border);
    padding: 48px 24px;
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 32px;
}

.footer-brand {
    font-family: var(--mono);
    font-size: 1.1rem;
    color: var(--green);
}

.footer-brand p {
    font-family: var(--font);
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 8px;
}

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

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
}

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

.footer-copy {
    color: var(--text-muted);
    font-size: 0.8rem;
    border-top: 1px solid var(--border);
    padding-top: 24px;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links a:not(.btn) { display: none; }

    .comparison { grid-template-columns: 1fr; }
    .steps { grid-template-columns: 1fr 1fr; }
    .lab-stats { grid-template-columns: 1fr 1fr; }
    .skills-grid { grid-template-columns: 1fr 1fr; }
    .pricing-grid { grid-template-columns: 1fr; }
    .price-card.featured { transform: none; }
    .footer-inner { flex-direction: column; gap: 24px; }

    .cta-form {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .steps { grid-template-columns: 1fr; }
    .lab-stats { grid-template-columns: 1fr 1fr; }
    .skills-grid { grid-template-columns: 1fr; }
}

/* Credentials Box */
.credentials-box {
    background: var(--bg-card);
    border: 1px solid var(--green-dim);
    border-radius: var(--radius);
    padding: 32px;
    max-width: 500px;
    margin: 32px auto 0;
    text-align: left;
}

.cred-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
}

.cred-item:last-child { border: none; }

.cred-label {
    color: var(--text-muted);
    font-size: 0.85rem;
    min-width: 90px;
}

.cred-value {
    background: var(--bg-dark);
    padding: 6px 12px;
    border-radius: 6px;
    font-family: var(--mono);
    font-size: 0.85rem;
    color: var(--green);
    flex: 1;
}

.copy-btn {
    background: var(--green-dim);
    color: white;
    border: none;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: background 0.2s;
}

.copy-btn:hover { background: var(--green); }