/* ── Reset ────────────────────────────────────────────── */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg: #0b1929;
    --surface: rgba(255,255,255,0.04);
    --surface-hover: rgba(255,255,255,0.07);
    --border: rgba(255,255,255,0.08);
    --text: #c9d1d9;
    --text-dim: #7d8590;
    --accent: #58a6b1;
    --accent-light: #7ec8d3;
    --good: #3fb68b;
    --neutral: #d4a850;
    --bad: #d07840;
    --blocker: #cf5050;
}

html { scroll-behavior: smooth; }

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

a {
    color: var(--accent-light);
    text-decoration: none;
}
a:hover { text-decoration: underline; }

code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85em;
    background: rgba(255,255,255,0.06);
    padding: 1px 6px;
    border-radius: 4px;
}

.container {
    max-width: 860px;
    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(11,25,41,0.88);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.nav-inner {
    max-width: 860px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 52px;
}

.nav-logo {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text);
    letter-spacing: -0.01em;
}
.nav-logo:hover { color: var(--accent-light); text-decoration: none; }

.nav-links {
    display: flex;
    gap: 24px;
    font-size: 0.84rem;
}
.nav-links a {
    color: var(--text-dim);
}
.nav-links a:hover {
    color: var(--text);
    text-decoration: none;
}

/* ── Hero ──────────────────────────────────────────────── */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 100px 24px 80px;
    position: relative;
}

.hero-content {
    max-width: 580px;
    position: relative;
    z-index: 2;
}

.hero h1 {
    font-size: 3.2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: #e6edf3;
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 1.05rem;
    color: var(--text-dim);
    line-height: 1.7;
    margin-bottom: 36px;
}

.grade-demo {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 36px;
}

.grade-card {
    width: 42px;
    height: 42px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.05rem;
    animation: bob 4s ease-in-out infinite;
}
.grade-card:nth-child(2) { animation-delay: 0.4s; }
.grade-card:nth-child(3) { animation-delay: 0.8s; }
.grade-card:nth-child(4) { animation-delay: 1.2s; }
.grade-card:nth-child(5) { animation-delay: 1.6s; }

@keyframes bob {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
}

.grade-a { background: rgba(63,182,139,0.12); color: var(--good); border: 1px solid rgba(63,182,139,0.2); }
.grade-b { background: rgba(88,166,177,0.12); color: var(--accent-light); border: 1px solid rgba(88,166,177,0.2); }
.grade-c { background: rgba(212,168,80,0.12); color: var(--neutral); border: 1px solid rgba(212,168,80,0.2); }
.grade-d { background: rgba(208,120,64,0.12); color: var(--bad); border: 1px solid rgba(208,120,64,0.2); }
.grade-f { background: rgba(207,80,80,0.12); color: var(--blocker); border: 1px solid rgba(207,80,80,0.2); }

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 11px 24px;
    background: var(--accent);
    color: #fff;
    font-family: inherit;
    font-size: 0.92rem;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.15s;
}
.cta-button:hover { background: #4d95a0; }

/* ── Sections ─────────────────────────────────────────── */
.section {
    padding: 80px 0;
    position: relative;
    z-index: 2;
}
.section-alt { background: rgba(255,255,255,0.015); }

.section-title {
    font-size: 1.6rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 8px;
    color: #e6edf3;
}

.section-lead {
    color: var(--text-dim);
    max-width: 540px;
    margin: 0 auto 48px;
    font-size: 0.95rem;
    text-align: center;
}

/* ── Pipeline ─────────────────────────────────────────── */
.pipeline {
    display: flex;
    flex-direction: column;
    gap: 0;
    margin-bottom: 64px;
}

.pipeline-step {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 22px 26px;
}
.pipeline-step:hover { background: var(--surface-hover); }

.pipeline-step h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: #e6edf3;
}

.pipeline-step p {
    color: var(--text-dim);
    font-size: 0.9rem;
    line-height: 1.65;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: rgba(88,166,177,0.12);
    color: var(--accent-light);
    font-weight: 600;
    font-size: 0.78rem;
    margin-bottom: 10px;
}

.pipeline-arrow {
    display: flex;
    justify-content: center;
    padding: 4px 0;
}
.pipeline-arrow::after {
    content: '';
    display: block;
    width: 1px;
    height: 16px;
    background: var(--border);
}

/* ── Tags ─────────────────────────────────────────────── */
.tag {
    display: inline-block;
    padding: 1px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
}
.tag.good { background: rgba(63,182,139,0.1); color: var(--good); }
.tag.neutral { background: rgba(212,168,80,0.1); color: var(--neutral); }
.tag.bad { background: rgba(208,120,64,0.1); color: var(--bad); }
.tag.blocker { background: rgba(207,80,80,0.1); color: var(--blocker); }

/* ── Tech Grid ────────────────────────────────────────── */
.tech-details h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 20px;
    text-align: center;
    color: #e6edf3;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
}

.tech-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px 22px;
}

.tech-card h4 {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--accent-light);
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.tech-card p {
    color: var(--text-dim);
    font-size: 0.88rem;
    line-height: 1.6;
}

/* ── Grading ──────────────────────────────────────────── */
.grade-table {
    max-width: 560px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.grade-row {
    display: flex;
    align-items: center;
    gap: 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px 20px;
}
.grade-row:hover { background: var(--surface-hover); }

.grade-letter {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.grade-info strong {
    font-size: 0.88rem;
    display: block;
    margin-bottom: 2px;
    color: #e6edf3;
}

.grade-info p {
    color: var(--text-dim);
    font-size: 0.85rem;
    line-height: 1.5;
}

/* ── Install Steps ────────────────────────────────────── */
.install-steps {
    max-width: 560px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.install-step {
    display: flex;
    gap: 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 22px 24px;
}

.install-step-number {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    font-weight: 600;
    font-size: 0.88rem;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.install-step-content h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 4px;
    color: #e6edf3;
}

.install-step-content p {
    color: var(--text-dim);
    font-size: 0.88rem;
    margin-bottom: 8px;
}
.install-step-content p:last-child { margin-bottom: 0; }

.code-block {
    display: inline-block;
    font-family: 'JetBrains Mono', monospace;
    background: rgba(0,0,0,0.25);
    border: 1px solid var(--border);
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 0.85rem;
    color: var(--accent-light);
    margin: 4px 0;
    user-select: all;
}

.download-button {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    background: var(--accent);
    color: #fff;
    font-weight: 600;
    font-size: 0.85rem;
    border-radius: 7px;
    transition: background 0.15s;
}
.download-button:hover { background: #4d95a0; text-decoration: none; color: #fff; }

/* ── GitHub ────────────────────────────────────────────── */
.github-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 22px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-weight: 500;
    font-size: 0.92rem;
    transition: background 0.15s;
}
.github-button:hover { background: var(--surface-hover); text-decoration: none; color: var(--text); }

/* ── Footer ────────────────────────────────────────────── */
.footer {
    text-align: center;
    padding: 36px 24px;
    border-top: 1px solid var(--border);
    position: relative;
    z-index: 2;
    color: var(--text-dim);
    font-size: 0.84rem;
}

/* ── Sea Creatures ─────────────────────────────────────── */
.ocean-life {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 1;
    overflow: hidden;
}

.creature {
    position: absolute;
    opacity: 0;
    animation-fill-mode: forwards;
}

/* Jellyfish drift downward with gentle sway */
.c-jelly1 {
    width: 55px;
    animation: jelly-drift1 28s linear infinite, jelly-sway 7s ease-in-out infinite;
}
.c-jelly2 {
    width: 45px;
    animation: jelly-drift2 34s linear infinite, jelly-sway 9s ease-in-out infinite;
    animation-delay: -12s, 0s;
}

@keyframes jelly-drift1 {
    0%   { left: 8%;  top: -12%; opacity: 0; }
    5%   { opacity: 0.5; }
    90%  { opacity: 0.5; }
    100% { left: 12%; top: 110%; opacity: 0; }
}
@keyframes jelly-drift2 {
    0%   { left: 75%; top: -12%; opacity: 0; }
    5%   { opacity: 0.4; }
    90%  { opacity: 0.4; }
    100% { left: 70%; top: 110%; opacity: 0; }
}
@keyframes jelly-sway {
    0%, 100% { transform: translateX(0); }
    50%      { transform: translateX(20px); }
}

/* Fish swim horizontally — face direction of travel */
.c-fish1 {
    width: 55px;
    top: 28%;
    animation: swim-right 22s linear infinite;
}
.c-fish2 {
    width: 48px;
    top: 62%;
    animation: swim-left 19s linear infinite;
    animation-delay: -6s;
}
.c-fish3 {
    width: 40px;
    top: 82%;
    animation: swim-right 25s linear infinite;
    animation-delay: -14s;
}

/* Fish SVGs face left by default (eye on left, tail on right).
   swim-right flips them so they face the direction of travel. */
@keyframes swim-right {
    0%   { left: -80px; opacity: 0; transform: scaleX(-1); }
    3%   { opacity: 0.55; }
    95%  { opacity: 0.55; }
    100% { left: calc(100% + 80px); opacity: 0; transform: scaleX(-1); }
}

/* swim-left: natural SVG orientation (facing left) */
@keyframes swim-left {
    0%   { left: calc(100% + 80px); opacity: 0; transform: scaleX(1); }
    3%   { opacity: 0.5; }
    95%  { opacity: 0.5; }
    100% { left: -80px; opacity: 0; transform: scaleX(1); }
}

/* Turtle SVG faces right, swims rightward — no flip needed */
.c-turtle {
    width: 70px;
    top: 48%;
    animation: turtle-swim 38s linear infinite;
    animation-delay: -18s;
}

@keyframes turtle-swim {
    0%   { left: -100px; opacity: 0; }
    3%   { opacity: 0.45; }
    95%  { opacity: 0.45; }
    100% { left: calc(100% + 100px); opacity: 0; }
}

/* Octopus drifts down slowly */
.c-octopus {
    width: 55px;
    animation: octo-drift 42s linear infinite, jelly-sway 12s ease-in-out infinite;
    animation-delay: -22s, 0s;
}

@keyframes octo-drift {
    0%   { left: 88%; top: -15%; opacity: 0; }
    4%   { opacity: 0.35; }
    92%  { opacity: 0.35; }
    100% { left: 82%; top: 110%; opacity: 0; }
}

/* ── Bubbles ───────────────────────────────────────────── */
.bubbles {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.bubble {
    position: absolute;
    bottom: -10px;
    border-radius: 50%;
    background: radial-gradient(circle at 30% 30%, rgba(255,255,255,0.07), transparent);
    border: 1px solid rgba(255,255,255,0.04);
    animation: rise linear infinite;
}

@keyframes rise {
    0%   { bottom: -10px; opacity: 0; }
    8%   { opacity: 1; }
    88%  { opacity: 1; }
    100% { bottom: 105vh; opacity: 0; }
}

/* ── Responsive ────────────────────────────────────────── */
@media (max-width: 768px) {
    .hero h1 { font-size: 2.4rem; }
    .tech-grid { grid-template-columns: 1fr; }
    .grade-row { flex-direction: column; text-align: center; }
    .install-step { flex-direction: column; }
    .nav-links { gap: 14px; font-size: 0.8rem; }
}

@media (max-width: 480px) {
    .hero h1 { font-size: 1.9rem; }
    .nav-links a:nth-child(-n+2) { display: none; }
    .section { padding: 56px 0; }
    .grade-card { width: 36px; height: 36px; font-size: 0.95rem; }
}