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

:root {
  /* Swap this variable to your own typeface */
  --font: 'Inter', system-ui, sans-serif;
  --font-heading: 'Space Mono', monospace;

  --bg: #030303;
  --surface: rgba(255,255,255,0.03);
  --surface-hover: rgba(255,255,255,0.05);
  --text: #efefef;
  --text-muted: #8d96a3;
  --text-faint: #7c7c7c;
  --accent: #df6823;
  --accent-warm: #e05b30;
  --border: rgba(255,255,255,0.06);
  --border-strong: rgba(255,255,255,0.1);
  --max-width: 1200px;
  --radius: 4px;
  --nav-h: 80px;
}

html { font-size: 16px; scroll-behavior: smooth; }

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

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  letter-spacing: -0.01em;
}

/* ── Layout ── */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 40px;
}

/* ── Nav ── */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  transition: background 0.5s ease, border-color 0.5s ease;
  border-bottom: 1px solid transparent;
}

nav.scrolled {
  background: rgba(3, 3, 3, 0.60);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom-color: var(--border);
}

nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

nav .logo img { height: 34px; }

nav ul {
  display: flex;
  gap: 40px;
  list-style: none;
}

nav ul a {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  transition: color 0.2s;
}

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

/* ── Gradient utilities ── */
.gradient-text {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-warm) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── Tag / Label ── */
.tag {
  display: inline-block;
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid rgba(192, 57, 43, 0.3);
  padding: 3px 10px;
  margin-bottom: 20px;
  border-radius: var(--radius);
}

/* ── Section ── */
section {
  padding: 80px 0;
  border-bottom: 1px solid var(--border);
}

section h2 {
  font-size: clamp(1.4rem, 2.5vw, 2.2rem);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 24px;
}

section p {
  color: var(--text);
  margin-bottom: 16px;
  font-size: 1rem;
  line-height: 1.8;
}

/* ── Block type system ── */
/* Text block: primary reading content */
.text-block { color: var(--text); font-size: 1rem; line-height: 1.8; }
/* Info block: captions, framing, secondary context */
.text-info  { color: var(--text-muted); font-size: 0.95rem; line-height: 1.75; }
/* Label: uppercase metadata, not prose */
.text-label { color: var(--text-muted); font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; }

/* ── Image Grids ── */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 32px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 32px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-top: 32px; }

.grid-2 img,
.grid-3 img,
.grid-4 img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}

/* ── Image Placeholder with shimmer ── */
.img-placeholder {
  width: 100%;
  aspect-ratio: 4/3;
  background: var(--surface);
  border: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}

.img-placeholder::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    105deg,
    transparent 40%,
    rgba(255, 255, 255, 0.04) 50%,
    transparent 60%
  );
  transform: translateX(-100%);
  animation: shimmer 2.8s ease-in-out infinite;
}

@keyframes shimmer {
  0%   { transform: translateX(-100%); }
  60%  { transform: translateX(100%); }
  100% { transform: translateX(100%); }
}

/* ── Footer ── */
footer {
  padding: 48px 0;
  text-align: center;
  color: var(--text-faint);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border-top: 1px solid var(--border);
}

/* ── Scroll Reveal ── */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition:
    opacity 0.75s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.75s cubic-bezier(0.22, 1, 0.36, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.08s; }
.reveal-delay-2 { transition-delay: 0.16s; }
.reveal-delay-3 { transition-delay: 0.24s; }
.reveal-delay-4 { transition-delay: 0.32s; }
.reveal-delay-5 { transition-delay: 0.40s; }
.reveal-delay-6 { transition-delay: 0.48s; }

/* ──────────────────────────────────────────────────────────
   STUDENT SHOWCASE — shared design system
   Reference page: gabby-overhand.html
   ────────────────────────────────────────────────────────── */

/* ── Extended tokens (student showcase) ── */
:root {
  --text-cream: #edecde;
  --text-sepia: #b2ad9e;
  --red: rgba(220,60,60,1);
  --red-bg: rgba(220,60,60,0.05);
  --red-border: rgba(220,60,60,0.22);
  --transition-fast: 0.15s ease;
  --transition-base: 0.2s ease;
}

/* ── Typography ── */
h3 {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.4;
}

/* ── Content section ── */
.content-section { padding: 140px 0; border-bottom: none; }

/* ── Section text hierarchy ── */
.section-label { font-size: 0.72rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 14px; }
.section-label.accent     { color: var(--accent); }
.section-label.accent-red { color: var(--red); }
.section-title  { font-family: var(--font-heading); font-size: clamp(1.8rem, 3.2vw, 3rem); font-weight: 400; line-height: 1.05; letter-spacing: -0.02em; margin-bottom: 20px; }
.section-prompt { font-size: 1rem; color: var(--text-cream); line-height: 1.8; margin-bottom: 40px; }
.section-body   { color: var(--text-cream); font-size: 1rem; line-height: 1.85; margin-bottom: 16px; }

/* ── Exchange block system (4-color) ── */
.exchange { display: flex; flex-direction: column; gap: 2px; margin-top: 40px; }
.exchange-prompt,
.exchange-response,
.exchange-note,
.exchange-before {
  display: flex; gap: 20px; padding: 20px 24px;
}
.exchange-prompt  { background: rgba(223,104,35,0.05); border: 1px solid rgba(223,104,35,0.22); }
.exchange-response{ background: rgba(94,168,224,0.05); border: 1px solid rgba(94,168,224,0.22); }
.exchange-note    { background: rgba(61,230,179,0.05); border: 1px solid rgba(61,230,179,0.22); }
.exchange-before  { background: var(--red-bg); border: 1px solid var(--red-border); }
.exchange-icon { font-size: 1rem; flex-shrink: 0; margin-top: 3px; line-height: 1.75; }
.exchange-prompt  .exchange-icon { color: var(--accent); }
.exchange-response.exchange-icon { color: #5ea8e0; }
.exchange-note    .exchange-icon { color: rgba(61,230,179,1); }
.exchange-before  .exchange-icon { color: var(--red); }
.exchange-label { font-size: 0.72rem; letter-spacing: 0.14em; text-transform: uppercase; margin-bottom: 8px; display: block; }
.exchange-prompt  .exchange-label { color: var(--accent); }
.exchange-response .exchange-label{ color: #5ea8e0; }
.exchange-note    .exchange-label { color: rgba(61,230,179,1); }
.exchange-before  .exchange-label { color: var(--red); }
.exchange-prompt  p,
.exchange-response p { font-size: 0.98rem; color: var(--text-cream); line-height: 1.75; }
.exchange-note  p,
.exchange-before p  { font-size: 0.98rem; color: var(--text-sepia); line-height: 1.75; }

/* ── Tools bar ── */
.section-tools-bar,
.section-tools-bar-left {
  display: flex;
  flex-direction: column;
  gap: 10px;
  position: absolute;
  right: 40px;
  top: 140px;
  width: 80px;
  align-items: center;
}
.section-tools-bar-left { right: auto; left: 0; align-items: center; }
.tools-bar-label { font-size: 0.6rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-faint); text-align: center; margin-bottom: 4px; }
.tool-chip { display: flex; flex-direction: column; align-items: center; gap: 7px; position: relative; }
.tool-chip-icon { width: 36px; height: 36px; border-radius: 8px; display: flex; align-items: center; justify-content: center; overflow: hidden; }
.tool-chip-icon img { width: 24px; height: 24px; object-fit: contain; }
.tool-chip-name { font-size: 0.6rem; letter-spacing: 0.08em; text-transform: uppercase; text-align: center; line-height: 1.3; }

/* Tool chip tooltip (tap on mobile) */
.tool-tooltip {
  position: absolute; bottom: calc(100% + 8px); left: 50%; transform: translateX(-50%);
  background: rgba(20,18,16,0.96); border: 1px solid var(--border-strong);
  color: var(--text-cream); font-size: 0.68rem; letter-spacing: 0.06em;
  white-space: nowrap; padding: 5px 10px; pointer-events: none;
  opacity: 0; transition: opacity 0.15s ease; z-index: 50;
}
.tool-chip.tip-active .tool-tooltip { opacity: 1; }

/* ── Back to top ── */
.back-to-top {
  position: fixed; right: 28px; bottom: 32px;
  width: 44px; height: 44px; border-radius: 50%;
  background: rgba(30,28,26,0.85); border: 1px solid rgba(255,255,255,0.1);
  color: var(--text-sepia); font-size: 1rem;
  display: flex; align-items: center; justify-content: center;
  text-decoration: none; z-index: 100;
  opacity: 0; pointer-events: none;
  transition: opacity var(--transition-base), background 0.2s ease, color 0.2s ease;
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { background: rgba(220,60,60,0.88); color: var(--text-cream); border-color: rgba(220,60,60,0.4); }

/* ── Seed / lever cards ── */
.card-grid-levers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 32px; }
.seed-card { background: var(--bg); padding: 24px; position: relative; border: 1px solid rgba(255,255,255,0.13); box-shadow: 0 1px 3px rgba(0,0,0,0.3), 0 4px 12px rgba(0,0,0,0.2), inset 0 1px 0 rgba(255,255,255,0.04); }
.seed-card .card-num { position: absolute; top: 14px; right: 16px; font-size: 0.72rem; color: var(--accent); letter-spacing: 0.1em; }
.seed-card h4 { font-family: var(--font-heading); font-size: 0.75rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text); margin-bottom: 12px; }
.seed-card p   { font-size: 0.95rem; color: var(--text-sepia); line-height: 1.75; }

/* ── Section background gradient (mobile visual separator) ── */
@media (max-width: 900px) {
  .content-section { background: linear-gradient(180deg, rgba(255,255,255,0.0) 0%, rgba(255,255,255,0.018) 50%, rgba(255,255,255,0.0) 100%); }
  .content-section:nth-child(even) { background: transparent; }
}

/* ── Mobile responsive ── */
@media (max-width: 900px) {
  .content-section { padding: 100px 0; }
  .container { padding: 0 32px; }
  .section-tools-bar, .section-tools-bar-left {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 32px;
    padding: 0 32px;
    width: auto;
    box-sizing: border-box;
  }
  .tools-bar-label { display: none; }
  .card-grid-levers { grid-template-columns: repeat(2, 1fr); }
  h3 { font-size: 1.15rem; font-weight: 700; letter-spacing: 0.01em; }
}

@media (max-width: 560px) {
  .content-section { padding: 72px 0; }
  .container { padding: 0 20px; }
  .section-tools-bar, .section-tools-bar-left {
    padding: 0 20px;
    gap: 10px;
  }
  .tool-chip-name { display: none; }
  .card-grid-levers { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  h3 { font-size: 1.1rem; font-weight: 700; letter-spacing: 0.01em; }
  .back-to-top { right: 16px; bottom: 20px; }
  .nav-links { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .reveal { transition: none; }
}