/* =========================================================
   landing.css — styles for the educational landing page.
   ========================================================= */

/* ---------- Hero ---------- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 64px;
    padding: 60px 48px;
    overflow: hidden;
    background: var(--bg);
}

.hero-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
    overflow: hidden;
}

.hero-grid {
    position: absolute;
    inset: 0;
    color: var(--text-faint);
}

.hero-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.35;
    animation: orb-float 12s ease-in-out infinite alternate;
}

.hero-orb--1 {
    width: 500px;
    height: 500px;
    background: var(--c1);
    top: -10%;
    left: -5%;
    animation-duration: 14s;
}

.hero-orb--2 {
    width: 450px;
    height: 450px;
    background: var(--c2);
    top: 30%;
    right: -8%;
    animation-delay: -4s;
    animation-duration: 16s;
}

.hero-orb--3 {
    width: 350px;
    height: 350px;
    background: var(--c3);
    bottom: -10%;
    left: 25%;
    animation-delay: -8s;
    animation-duration: 18s;
}

@keyframes orb-float {
    0% {
        transform: translate(0, 0) scale(1);
    }

    50% {
        transform: translate(30px, -20px) scale(1.08);
    }

    100% {
        transform: translate(-20px, 30px) scale(0.95);
    }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 540px;
    flex-shrink: 0;
}

.hero-badge {
    display: inline-block;
    background: var(--accent-soft);
    color: var(--accent-strong);
    font-weight: 600;
    font-size: 0.78rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    padding: 6px 14px;
    border-radius: 100px;
    margin-bottom: 20px;
    border: 1px solid var(--border);
}

.hero-title {
    font-size: clamp(2.4rem, 5vw, 3.8rem);
    font-weight: 800;
    line-height: 1.08;
    letter-spacing: -0.03em;
    color: var(--text);
    margin-bottom: 18px;
}

.hero-gradient {
    background: linear-gradient(135deg, var(--accent) 0%, var(--c4) 50%, var(--c1) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.1rem;
    line-height: 1.65;
    color: var(--text-muted);
    margin-bottom: 32px;
    max-width: 480px;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 14px;
    flex-wrap: wrap;
}

.btn-hero {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--accent);
    color: #fff;
    padding: 14px 28px;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(58, 109, 240, 0.35);
    transition: transform 0.15s ease, box-shadow 0.25s ease, background 0.2s ease;
}

.btn-hero:hover {
    background: var(--accent-strong);
    box-shadow: 0 6px 28px rgba(58, 109, 240, 0.45);
    transform: translateY(-2px);
    text-decoration: none;
}

.btn-hero:active {
    transform: translateY(0);
}

.btn-hero-ghost {
    display: inline-flex;
    align-items: center;
    padding: 14px 24px;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    text-decoration: none;
    border: 1px solid var(--border-strong);
    background: var(--surface);
    transition: all 0.15s ease;
}

.btn-hero-ghost:hover {
    background: var(--bg-soft);
    border-color: var(--accent);
    color: var(--accent-strong);
    text-decoration: none;
}

.hero-visual {
    position: relative;
    z-index: 2;
    flex-shrink: 0;
}

.hero-visual canvas {
    width: 420px;
    height: 420px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    background: #fff;
    box-shadow: var(--shadow-lg);
    cursor: default;
}

/* ---------- Landing nav (sticky) ---------- */
.landing-nav {
    position: sticky;
    top: 0;
    z-index: 30;
    background: rgba(246, 248, 251, 0.85);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}

:root[data-theme="dark"] .landing-nav {
    background: rgba(11, 18, 32, 0.85);
}

.landing-nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 0 28px;
    height: 56px;
}

.landing-nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text);
    flex-shrink: 0;
}

.landing-nav-links {
    display: flex;
    gap: 6px;
    margin-left: auto;
}

.landing-nav-links a {
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--text-muted);
    text-decoration: none;
    transition: all 0.15s ease;
}

.landing-nav-links a:hover {
    background: var(--bg-soft);
    color: var(--text);
    text-decoration: none;
}

.landing-nav-actions {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: 12px;
}

/* ---------- Educational sections ---------- */
.edu-section {
    padding: 80px 28px;
}

.edu-section--alt {
    background: var(--bg-soft);
}

:root[data-theme="dark"] .edu-section--alt {
    background: var(--surface-2);
}

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

.section-tag {
    display: inline-block;
    font-size: 0.74rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 10px;
}

.edu-section h2 {
    font-size: 1.6rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 14px;
    color: var(--text);
}

.section-intro {
    font-size: 1.02rem;
    color: var(--text-muted);
    max-width: 700px;
    margin-bottom: 32px;
    line-height: 1.65;
}

/* --- About (2-column layout) --- */
.edu-columns {
    display: grid;
    grid-template-columns: 1fr 340px;
    gap: 32px;
    align-items: start;
}

.edu-text p {
    font-size: 1rem;
    line-height: 1.72;
    color: var(--text-muted);
    margin: 0 0 16px;
}

.edu-highlight-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.edu-highlight-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), var(--c4));
}

.highlight-icon {
    width: 52px;
    height: 52px;
    border-radius: var(--radius);
    background: var(--accent-soft);
    display: grid;
    place-items: center;
    margin-bottom: 14px;
    color: var(--accent);
}

.edu-highlight-card h3 {
    font-size: 1rem;
    margin-bottom: 8px;
    color: var(--text);
}

.edu-highlight-card p {
    font-size: 0.92rem;
    line-height: 1.6;
    color: var(--text-muted);
}

/* --- Kernel cards --- */
.kernel-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 18px;
}

.kernel-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.kernel-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.kernel-card-accent {
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--accent-c, var(--accent));
    border-radius: 4px 0 0 4px;
}

.kernel-card h3 {
    font-size: 1rem;
    color: var(--text);
    margin-bottom: 8px;
}

.kernel-card .formula {
    margin: 0 0 12px;
}

.kernel-card p:not(.formula) {
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--text-muted);
    margin: 0;
}

/* --- Strategy grid (multi-class) --- */
.strategy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.strategy-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
    box-shadow: var(--shadow-sm);
    position: relative;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.strategy-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.strategy-badge {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    padding: 4px 12px;
    border-radius: 100px;
    margin-bottom: 12px;
}

.strategy-badge--ova {
    background: rgba(190, 143, 11, 0.12);
    color: #cc7d0e;
}

.strategy-badge--ovo {
    background: rgba(168, 85, 247, 0.12);
    color: #7c3aed;
}

:root[data-theme="dark"] .strategy-badge--ova {
    color: #cc7d0e;
}

:root[data-theme="dark"] .strategy-badge--ovo {
    color: #c084fc;
}

.strategy-card h3 {
    font-size: 1.05rem;
    margin-bottom: 10px;
    color: var(--text);
}

.strategy-card>p {
    font-size: 0.92rem;
    line-height: 1.65;
    color: var(--text-muted);
    margin: 0 0 16px;
}

.strategy-pros-cons {
    display: grid;
    gap: 10px;
}

.strategy-pro,
.strategy-con {
    font-size: 0.86rem;
    line-height: 1.55;
    color: var(--text-muted);
    padding: 10px 12px;
    border-radius: var(--radius-sm);
}

.strategy-pro {
    background: rgba(16, 185, 129, 0.06);
    border-left: 3px solid #10b981;
}

.strategy-con {
    background: rgba(239, 68, 68, 0.05);
    border-left: 3px solid #ef4444;
}

.strategy-tip {
    padding: 14px 18px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.92rem;
    color: var(--text-muted);
    box-shadow: var(--shadow-sm);
}

/* ---------- CTA footer ---------- */
.cta-section {
    padding: 80px 28px;
    text-align: center;
    background: var(--bg);
    border-top: 1px solid var(--border);
}

.cta-inner {
    max-width: 560px;
    margin: 0 auto;
}

.cta-inner h2 {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 10px;
    color: var(--text);
}

.cta-inner p {
    font-size: 1.05rem;
    color: var(--text-muted);
    margin-bottom: 28px;
    line-height: 1.6;
}

.cta-inner .btn-hero {
    margin: 0 auto;
}

/* ---------- Back link (simulation topbar) ---------- */
.back-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    transition: all 0.15s ease;
    flex-shrink: 0;
}

.back-link:hover {
    background: var(--bg-soft);
    color: var(--text);
    text-decoration: none;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
    .hero {
        flex-direction: column;
        gap: 40px;
        padding: 48px 24px;
        text-align: center;
    }

    .hero-content {
        max-width: 100%;
    }

    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-visual canvas {
        width: min(90vw, 380px);
        height: min(90vw, 380px);
    }

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

    .landing-nav-links {
        display: none;
    }
}

@media (max-width: 600px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-visual canvas {
        width: min(85vw, 320px);
        height: min(85vw, 320px);
    }

    .edu-section {
        padding: 48px 16px;
    }

    .landing-nav-inner {
        padding: 0 16px;
    }

    .landing-nav-actions .btn-train {
        padding: 6px 12px;
        font-size: 0.82rem;
        white-space: nowrap;
        min-width: 100px;
        text-align: center;
        justify-content: center;
    }

    .landing-nav-actions .btn-theme {
        min-width: 58px;
        text-align: center;
    }
}

.github-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2.5rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 1.5rem;
    padding: 2.75rem 3rem;
    position: relative;
    overflow: hidden;
    box-shadow: 0 8px 40px rgba(0,0,0,0.08), 0 1px 0 rgba(255,255,255,0.6) inset;
    transition: box-shadow 0.25s ease, transform 0.2s ease;
}

.github-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 16px 56px rgba(0,0,0,0.12), 0 1px 0 rgba(255,255,255,0.6) inset;
}

/* Rainbow top border */
.github-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent) 0%, var(--c4) 40%, var(--c2) 70%, var(--c1) 100%);
}

/* Subtle background glow */
.github-card::after {
    content: '';
    position: absolute;
    top: -80px; right: -80px;
    width: 280px; height: 280px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(58,109,240,0.07) 0%, transparent 70%);
    pointer-events: none;
}

.github-card-left {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    position: relative;
    z-index: 1;
}

.github-icon-wrap {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--accent), var(--c4));
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 16px rgba(58,109,240,0.3);
}

.github-card-text .section-tag {
    margin-bottom: 6px;
}

.github-card-text h2 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.02em;
    margin: 0 0 6px;
}

.github-card-text p {
    font-size: 0.93rem;
    color: var(--text-muted);
    line-height: 1.6;
    margin: 0;
    max-width: 520px;
}

.github-tag {
    font-size: 0.72rem;
    font-weight: 600;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    background: var(--bg-soft, rgba(37,99,235,0.07));
    color: var(--accent);
    border: 1px solid var(--border);
    letter-spacing: 0.01em;
    transition: background 0.15s ease, border-color 0.15s ease;
}

.github-tag:hover {
    background: rgba(58,109,240,0.12);
    border-color: var(--accent);
}

.github-card-btn {
    flex-shrink: 0;
    white-space: nowrap;
    position: relative;
    z-index: 1;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 26px;
    background: var(--bg);
    border: 1.5px solid var(--border-strong, rgba(58,109,240,0.25));
    border-radius: var(--radius);
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text);
    text-decoration: none;
    transition: all 0.2s ease;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.github-card-btn:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    box-shadow: 0 6px 24px rgba(58,109,240,0.35);
    transform: translateY(-1px);
    text-decoration: none;
}

@media (max-width: 700px) {
    .github-card {
        flex-direction: column;
        align-items: flex-start;
        padding: 2rem;
    }
    .github-card-btn {
        width: 100%;
        justify-content: center;
    }
}