/* ══════════════════════════════════════════════════════════
   PREPVERSE — PRECISION DESIGN SYSTEM v7.0
   Off-White · Professional · Engineering-Grade
══════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Instrument+Serif:ital@0;1&display=swap');

/* ── TOKENS ─────────────────────────────────────────────── */
:root {
    /* Background */
    --bg:          #F8F8F6;
    --surface:     #FFFFFF;
    --surface-2:   #F1F1EE;
    --surface-3:   #E8E8E4;

    /* Brand */
    --indigo:      #4338CA;
    --indigo-mid:  #6366F1;
    --indigo-light:#EEF2FF;
    --teal:        #0D9488;
    --teal-light:  #CCFBF1;

    /* Text */
    --ink:         #0D1117;
    --ink-2:       #374151;
    --ink-3:       #6B7280;
    --ink-4:       #9CA3AF;

    /* Borders */
    --border:      rgba(0,0,0,0.06);
    --border-md:   rgba(0,0,0,0.1);
    --border-dark: rgba(0,0,0,0.18);

    /* Shadows */
    --shadow-sm:   0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md:   0 4px 16px rgba(0,0,0,0.06), 0 2px 6px rgba(0,0,0,0.04);
    --shadow-lg:   0 20px 60px rgba(0,0,0,0.07), 0 8px 20px rgba(0,0,0,0.05);
    --shadow-xl:   0 40px 100px rgba(0,0,0,0.09);

    /* Accent glow */
    --glow-indigo: rgba(67,56,202,0.15);
    --glow-teal:   rgba(13,148,136,0.12);

    /* Motion */
    --ease:        cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in:     cubic-bezier(0.4, 0, 1, 1);

    /* Radius */
    --r-xs: 6px; --r-sm: 10px; --r-md: 14px; --r-lg: 20px; --r-xl: 28px;

    /* Spacing scale */
    --sp-1: 4px;  --sp-2: 8px;  --sp-3: 12px; --sp-4: 16px;
    --sp-5: 24px; --sp-6: 32px; --sp-7: 48px; --sp-8: 64px;
    --sp-9: 96px; --sp-10:128px;
}

/* ── RESET ───────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
    background: var(--bg);
    color: var(--ink-2);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; }
button { font-family: inherit; cursor: pointer; border: none; }

/* ── LAYOUT ─────────────────────────────────────────────── */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--sp-5);
}

/* ── BACKGROUND CANVAS ──────────────────────────────────── */
#bg-canvas {
    position: fixed; inset: 0;
    z-index: -1; width: 100%; height: 100%;
    pointer-events: none;
    opacity: 0.18;
    mask-image: linear-gradient(to bottom, rgba(0,0,0,0.6) 0%, rgba(0,0,0,0.4) 50%, transparent 100%);
    -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,0.6) 0%, rgba(0,0,0,0.4) 50%, transparent 100%);
}

/* ════════════════════════════════════════════
   NAVBAR
════════════════════════════════════════════ */
.navbar {
    position: fixed; top: 0; left: 0; right: 0;
    height: 72px; z-index: 900;
    display: flex; align-items: center;
    transition: all 0.35s var(--ease);
}
.navbar .container {
    display: flex; align-items: center; width: 100%;
}
.navbar.scrolled {
    height: 60px;
    background: rgba(248,248,246,0.88);
    backdrop-filter: blur(24px) saturate(1.8);
    -webkit-backdrop-filter: blur(24px) saturate(1.8);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 1px 0 var(--border);
}

.navbar-brand {
    display: flex; align-items: center; gap: 8px;
    text-decoration: none; font-weight: 800;
    font-size: 1.1875rem; color: var(--ink);
    letter-spacing: -0.02em;
}
.brand-dot {
    width: 9px; height: 9px;
    background: var(--indigo);
    border-radius: 50%;
    box-shadow: 0 0 0 2px rgba(67,56,202,0.2);
}

.navbar-menu {
    display: flex; align-items: center;
    list-style: none; gap: 4px; margin-left: auto;
}
.navbar-menu li a {
    display: block; padding: 7px 14px;
    text-decoration: none; font-size: 0.875rem;
    font-weight: 600; color: var(--ink-3);
    border-radius: var(--r-xs);
    transition: color 0.15s, background 0.15s;
}
.navbar-menu li a:hover { color: var(--ink); background: rgba(0,0,0,0.04); }
.navbar-menu li a.active { color: var(--indigo); }
.nav-divider { width: 1px; height: 18px; background: var(--border-md); margin: 0 8px; flex-shrink: 0; }

.nav-btn-login { color: var(--ink) !important; font-weight: 700 !important; }
.nav-btn-cta {
    background: var(--ink) !important; color: #fff !important;
    padding: 9px 18px !important; border-radius: var(--r-sm) !important;
    font-weight: 700 !important;
    transition: opacity 0.15s !important; letter-spacing: -0.01em;
}
.nav-btn-cta:hover { opacity: 0.82 !important; background: var(--ink) !important; }
.nav-btn-dash {
    background: var(--indigo) !important; color: #fff !important;
    padding: 9px 18px !important; border-radius: var(--r-sm) !important;
    font-weight: 700 !important;
}

.mobile-menu-btn {
    display: none; background: transparent; color: var(--ink); margin-left: auto;
}
.navbar-menu li { list-style: none; }

/* ════════════════════════════════════════════
   HERO
════════════════════════════════════════════ */
.hero-split {
    padding: 148px 0 100px;
    min-height: 100vh;
    display: flex;
    align-items: center;
}
.hero-grid {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 80px;
    align-items: center;
}
.hero-left {
    display: flex; flex-direction: column;
}

/* Status pill */
.status-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: var(--surface); border: 1px solid var(--border-md);
    padding: 5px 14px; border-radius: 100px;
    font-size: 0.75rem; font-weight: 700;
    color: var(--ink-3); margin-bottom: var(--sp-5);
    align-self: flex-start;
    box-shadow: var(--shadow-sm);
}
.status-dot {
    width: 6px; height: 6px; background: #10B981;
    border-radius: 50%; animation: dotPulse 2s infinite;
}
@keyframes dotPulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(16,185,129,0.4); }
    50% { box-shadow: 0 0 0 5px rgba(16,185,129,0); }
}

/* Hero title */
.hero-title {
    font-size: clamp(3rem, 5.5vw, 5rem);
    line-height: 1.04;
    font-weight: 800;
    color: var(--ink);
    letter-spacing: -0.04em;
    margin-bottom: var(--sp-5);
}
.hero-title-word { display: inline-block; white-space: nowrap; margin-right: 0.18em; }
.hero-letter {
    display: inline-block;
    opacity: 0; transform: translateY(28px);
    animation: letterIn 0.55s var(--ease) forwards;
}
@keyframes letterIn { to { opacity: 1; transform: translateY(0); } }
.hero-title em {
    font-style: normal; font-weight: 800;
    background: linear-gradient(120deg, var(--indigo) 0%, var(--indigo-mid) 40%, var(--teal) 100%);
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Hero sub */
.hero-sub {
    font-size: 1.125rem; color: var(--ink-3);
    line-height: 1.75; max-width: 480px;
    margin-bottom: var(--sp-6); font-weight: 400;
}

/* Hero CTA */
.hero-cta {
    display: flex; gap: 12px;
    margin-bottom: var(--sp-7); flex-wrap: wrap;
}

/* ── BUTTONS ── */
.btn-new {
    display: inline-flex; align-items: center; gap: 8px;
    height: 52px; padding: 0 26px; border-radius: var(--r-md);
    font-size: 0.9375rem; font-weight: 700; text-decoration: none;
    letter-spacing: -0.01em; position: relative; overflow: hidden;
    transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease), opacity 0.18s;
}
.btn-new svg { width: 17px; height: 17px; flex-shrink: 0; }
.btn-new:active { transform: scale(0.97) !important; }
.btn-filled {
    background: var(--indigo); color: #fff;
    box-shadow: 0 8px 20px -4px var(--glow-indigo),
                inset 0 1px 0 rgba(255,255,255,0.12);
}
.btn-filled:hover {
    transform: translateY(-2px);
    box-shadow: 0 14px 30px -6px var(--glow-indigo),
                inset 0 1px 0 rgba(255,255,255,0.12);
}
.btn-shimmer {
    position: absolute; top: 0; left: -80%; width: 60%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.18), transparent);
    transform: skewX(-15deg);
    animation: shimmer 3.5s ease-in-out infinite;
}
@keyframes shimmer { 0% { left:-80%; } 45%,100% { left:130%; } }

.btn-border {
    background: var(--surface); color: var(--ink);
    border: 1px solid var(--border-md);
    box-shadow: var(--shadow-sm);
}
.btn-border:hover {
    border-color: var(--indigo); color: var(--indigo);
    transform: translateY(-1px); box-shadow: var(--shadow-md);
}

/* Hero metrics */
.hero-metrics { display: flex; gap: 32px; align-items: center; }
.hero-metric { display: flex; flex-direction: column; }
.hero-metric-val {
    font-size: 1.75rem; font-weight: 800; color: var(--ink);
    letter-spacing: -0.04em; line-height: 1;
}
.hero-metric-label {
    font-size: 0.7rem; font-weight: 700; color: var(--ink-4);
    text-transform: uppercase; letter-spacing: 0.06em; margin-top: 5px;
}
.hero-metric-sep { width: 1px; height: 28px; background: var(--border-md); }

/* ── UI MOCKUP ── */
.hero-right {
    display: flex; align-items: center; justify-content: center;
}
.ui-mockup {
    background: var(--surface); border: 1px solid var(--border-md);
    border-radius: var(--r-xl); overflow: hidden;
    box-shadow: var(--shadow-xl);
    width: 100%; max-width: 440px;
    animation: floatY 7s ease-in-out infinite;
}
@keyframes floatY {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-14px); }
}

.mock-bar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 16px;
    background: var(--surface-2); border-bottom: 1px solid var(--border);
}
.mock-dots { display: flex; gap: 6px; }
.mock-dots span {
    width: 10px; height: 10px; border-radius: 50%; display: block;
}
.mock-title { font-size: 0.7rem; font-weight: 700; color: var(--ink-3); }
.mock-timer {
    display: flex; align-items: center; gap: 4px;
    font-size: 0.7rem; font-weight: 700; color: var(--teal); font-family: monospace;
}

.mock-body {
    display: grid; grid-template-columns: 1fr 1fr;
    min-height: 270px; overflow: hidden;
}
.mock-passage {
    padding: 18px 14px; border-right: 1px solid var(--border);
    display: flex; flex-direction: column; gap: 9px;
}
.mock-line {
    height: 8px; border-radius: 100px;
    background: var(--surface-3);
    animation: lineShimmer 3s ease-in-out infinite;
}
.mock-line.w-full { width: 100%; }
.mock-line.w-4\/5 { width: 80%; }
.mock-line.w-3\/5 { width: 60%; }
.mock-line.w-5\/6 { width: 83%; }
.mock-line.w-2\/3 { width: 67%; }
@keyframes lineShimmer { 0%,100%{opacity:.5} 50%{opacity:1} }

.mock-questions { padding: 16px 12px; display: flex; flex-direction: column; gap: 10px; }
.mock-q-title {
    font-size: 0.6rem; font-weight: 800; text-transform: uppercase;
    letter-spacing: 0.08em; color: var(--ink-4); margin-bottom: 4px;
}
.mock-q-item { display: flex; align-items: flex-start; gap: 8px; padding: 6px; border-radius: 6px; }
.mock-q-active { background: var(--indigo-light); border: 1px solid rgba(67,56,202,0.12); }
.mock-q-num {
    width: 18px; height: 18px; border-radius: 4px; background: var(--indigo);
    color: #fff; font-size: 0.6rem; font-weight: 900;
    display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.mock-answer { font-size: 0.69rem; font-weight: 600; color: var(--ink-2); margin-top: 4px; font-family: monospace; }
.typing-effect::after { content:'|'; color: var(--indigo); animation: blink 1s step-end infinite; }
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0} }

.mock-score-bar { padding: 12px 12px 14px; border-top: 1px solid var(--border); }
.progress {
    height: 4px; background: var(--surface-3); border-radius: 100px; overflow: hidden;
}
.progress-fill {
    height: 100%; background: linear-gradient(90deg, var(--indigo), var(--teal));
    border-radius: 100px;
}

.mock-badge {
    position: absolute;
    display: flex; align-items: center; gap: 6px;
    background: var(--surface); border: 1px solid var(--border-md);
    border-radius: var(--r-sm); padding: 8px 12px;
    font-size: 0.7rem; font-weight: 700; color: var(--ink-2);
    box-shadow: var(--shadow-md);
    white-space: nowrap;
}
.mock-badge-1 {
    bottom: -14px; left: -18px;
    animation: badgeFloat1 5s ease-in-out infinite;
}
.mock-badge-2 {
    top: 18px; right: -18px;
    animation: badgeFloat2 5s 1.2s ease-in-out infinite;
}
@keyframes badgeFloat1 { 0%,100%{transform:translate(0,0)} 50%{transform:translate(-3px,-8px)} }
@keyframes badgeFloat2 { 0%,100%{transform:translate(0,0)} 50%{transform:translate(3px,-6px)} }

/* ════════════════════════════════════════════
   SECTIONS
════════════════════════════════════════════ */
.section { padding: var(--sp-10) 0; }
.section-sm { padding: var(--sp-9) 0; }
.section-border { border-top: 1px solid var(--border); }

/* Section label + title pattern */
.section-label {
    display: inline-block; font-size: 0.72rem; font-weight: 800;
    text-transform: uppercase; letter-spacing: 0.1em; color: var(--indigo);
    margin-bottom: var(--sp-3);
}
.section-title {
    font-size: clamp(2rem, 3.5vw, 3rem); font-weight: 800;
    color: var(--ink); letter-spacing: -0.03em;
    line-height: 1.1; margin-bottom: var(--sp-4);
}
.section-desc { font-size: 1rem; color: var(--ink-3); max-width: 600px; }

/* ── MODULES GRID ── */
.modules-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}

/* ── FEATURES GRID ── */
.features-grid {
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}

/* ── STATS GRID ── */
.stats-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}

/* ── CARDS ── */
.card {
    background: var(--surface); border: 1px solid var(--border);
    border-radius: var(--r-md); transition: 0.25s var(--ease);
    box-shadow: var(--shadow-sm);
}
.card:hover {
    border-color: rgba(67,56,202,0.2);
    box-shadow: var(--shadow-lg), 0 0 0 3px rgba(67,56,202,0.05);
    transform: translateY(-5px);
}
.card-inner { padding: var(--sp-5); }
.card-icon {
    width: 40px; height: 40px; border-radius: var(--r-sm);
    background: var(--indigo-light); border: 1px solid rgba(67,56,202,0.12);
    color: var(--indigo); display: flex; align-items: center; justify-content: center;
    margin-bottom: var(--sp-4);
}
.card-title {
    font-size: 1rem; font-weight: 700; color: var(--ink);
    letter-spacing: -0.02em; margin-bottom: var(--sp-2);
}
.card-desc { font-size: 0.875rem; color: var(--ink-3); line-height: 1.65; margin-bottom: var(--sp-4); }
.card-link {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: 0.8rem; font-weight: 700; color: var(--indigo);
    text-decoration: none; transition: gap 0.15s;
}
.card-link:hover { gap: 10px; }

/* ── BADGES ── */
.badge {
    display: inline-flex; align-items: center;
    padding: 3px 10px; border-radius: 100px;
    font-size: 0.7rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.06em;
}
.badge-accent { background: var(--indigo-light); color: var(--indigo); }
.badge-teal { background: var(--teal-light); color: var(--teal); }

/* ── STAT CARDS ── */
.stat-card {
    background: var(--surface); border: 1px solid var(--border);
    border-radius: var(--r-md); padding: var(--sp-6);
    display: flex; flex-direction: column;
    box-shadow: var(--shadow-sm); transition: 0.25s var(--ease);
}
.stat-card:hover { border-color: var(--indigo); box-shadow: var(--shadow-md); }
.stat-label { font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-4); }
.stat-num {
    font-size: 3rem; font-weight: 800; color: var(--ink); letter-spacing: -0.05em; line-height: 1.1;
    margin-block: 8px;
}
.text-sm { font-size: 0.8rem; }
.text-muted { color: var(--ink-4); }
.teal-soft { background: var(--teal-light) !important; border-color: rgba(13,148,136,0.15) !important; }

/* ── REVEAL ── */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.active { opacity: 1; transform: translateY(0); }

/* ════════════════════════════════════════════
   FOOTER / CTA
════════════════════════════════════════════ */
.cta-section {
    padding: var(--sp-10) 0;
    background: var(--surface-2); border-top: 1px solid var(--border);
    text-align: center;
}
.cta-section h2 { font-size: clamp(2rem, 3.5vw, 2.75rem); font-weight: 800; letter-spacing: -0.03em; }
.cta-section p { color: var(--ink-3); margin: 16px auto 40px; max-width: 500px; }
.btn-white {
    display: inline-flex; align-items: center; gap: 10px;
    background: var(--ink); color: #fff;
    padding: 15px 34px; border-radius: var(--r-md);
    font-weight: 700; text-decoration: none; font-size: 0.95rem;
    letter-spacing: -0.01em;
    box-shadow: 0 10px 30px rgba(0,0,0,0.12);
    transition: 0.2s;
}
.btn-white:hover { opacity: 0.85; transform: translateY(-2px); }

.footer {
    padding: var(--sp-9) 0 var(--sp-6);
    border-top: 1px solid var(--border);
}
.footer-grid {
    display: grid; grid-template-columns: 1.8fr repeat(3, 1fr); gap: 60px;
}
.footer-brand {
    display: inline-flex; align-items: center; gap: 8px;
    font-size: 1.1rem; font-weight: 800; color: var(--ink);
    text-decoration: none; margin-bottom: var(--sp-4); letter-spacing: -0.02em;
}
.footer-brand span { color: var(--indigo); }
.footer-desc { font-size: 0.875rem; color: var(--ink-3); max-width: 280px; line-height: 1.7; }
.footer h4 {
    font-size: 0.72rem; font-weight: 800; text-transform: uppercase;
    letter-spacing: 0.1em; color: var(--ink); margin-bottom: var(--sp-4);
}
.footer ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.footer a { font-size: 0.875rem; color: var(--ink-3); text-decoration: none; transition: color 0.15s; }
.footer a:hover { color: var(--indigo); }
.footer-social {
    display: flex; gap: 8px; margin-top: var(--sp-4);
}
.footer-social a {
    width: 34px; height: 34px; border-radius: var(--r-xs);
    border: 1px solid var(--border-md);
    display: flex; align-items: center; justify-content: center;
    color: var(--ink-3); transition: 0.15s;
}
.footer-social a:hover { border-color: var(--indigo); color: var(--indigo); background: var(--indigo-light); }
.footer-bottom {
    display: flex; justify-content: space-between; align-items: center;
    padding-top: var(--sp-5); margin-top: var(--sp-8);
    border-top: 1px solid var(--border);
    font-size: 0.78rem; color: var(--ink-4);
}

/* ════════════════════════════════════════════
   RESPONSIVE
════════════════════════════════════════════ */
@media (max-width: 1024px) {
    .modules-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 40px; }
}
@media (max-width: 900px) {
    .hero-split { padding: 120px 0 80px; min-height: auto; }
    .hero-grid { grid-template-columns: 1fr; gap: 48px; text-align: center; }
    .hero-left { align-items: center; }
    .hero-title { font-size: 2.75rem; }
    .hero-sub { margin-left: auto; margin-right: auto; }
    .hero-cta { justify-content: center; }
    .hero-metrics { justify-content: center; }
    .status-badge { align-self: center; }
    .hero-right { display: none; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
    .modules-grid { grid-template-columns: 1fr; }
    .features-grid { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: 1fr 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }
    .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }
    .hero-cta { flex-direction: column; width: 100%; }
    .btn-new { justify-content: center; width: 100%; }
    .navbar-menu { display: none; }
    .mobile-menu-btn { display: flex; align-items: center; }
    .navbar-menu.active {
        display: flex; flex-direction: column; gap: 4px;
        position: fixed; top: 60px; left: 0; right: 0;
        background: var(--surface);
        border-bottom: 1px solid var(--border);
        padding: 12px;
    }
}