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

:root {
  --bg:#03060f; --bg2:#070d1a; --bg3:#0c1528;
  --border:rgba(255,255,255,0.08); --border-glow:rgba(99,179,237,0.3);
  --text:#e2e8f4; --text-dim:#7a8ba8;
  --galaxy:#f6ad55; --galaxy-glow:rgba(246,173,85,0.25);
  --qso:#63b3ed;    --qso-glow:rgba(99,179,237,0.25);
  --star:#68d391;   --star-glow:rgba(104,211,145,0.25);
  --accent:#63b3ed; --radius:12px;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Syne', sans-serif;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── Canvas Layers ── */
#nebula-canvas, #aurora-canvas, #starfield, #particle-canvas {
  position: fixed; inset: 0; pointer-events: none;
}
#nebula-canvas   { z-index: 0; }
#aurora-canvas   { z-index: 1; opacity: 0.5; }
#starfield       { z-index: 2; }
#particle-canvas { z-index: 100; }

body::after {
  content: ''; position: fixed; inset: 0; z-index: 3; pointer-events: none;
  background: repeating-linear-gradient(0deg, transparent, transparent 2px,
    rgba(0,0,0,0.025) 2px, rgba(0,0,0,0.025) 4px);
}

/* ── Layout ── */
.wrapper {
  position: relative; z-index: 4;
  max-width: 900px; margin: 0 auto;
  padding: clamp(24px, 5vw, 48px) clamp(16px, 4vw, 24px) 80px;
}

/* ── Header ── */
header {
  text-align: center; margin-bottom: clamp(32px, 5vw, 56px);
  animation: fadeDown 1s ease both; position: relative;
  overflow: hidden; padding: 20px 0;
}

.orbit-ring {
  position: absolute; top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: min(440px, 90vmin); height: min(440px, 90vmin);
  border: 1px solid rgba(99,179,237,0.06);
  border-radius: 50%; animation: spin 30s linear infinite; pointer-events: none;
}
.orbit-ring::before {
  content: '✦'; position: absolute; top: -9px; left: 50%;
  transform: translateX(-50%); color: var(--qso); font-size: 14px; opacity: 0.7;
}
.orbit-ring-2 {
  width: min(560px, 110vmin); height: min(560px, 110vmin);
  border-color: rgba(246,173,85,0.04);
  animation: spin 50s linear infinite reverse;
}
.orbit-ring-2::before { content: '✦'; color: var(--galaxy); opacity: 0.4; }
@keyframes spin { to { transform: translate(-50%,-50%) rotate(360deg); } }

.badge {
  display: inline-block; font-family: 'Space Mono', monospace;
  font-size: clamp(9px, 2vw, 11px); letter-spacing: 3px; text-transform: uppercase;
  color: var(--qso); border: 1px solid rgba(99,179,237,0.35);
  padding: 5px 14px; border-radius: 100px; margin-bottom: 20px;
  animation: pulse-border 3s ease-in-out infinite; position: relative;
}
@keyframes pulse-border {
  0%,100% { border-color: rgba(99,179,237,0.35); box-shadow: none; }
  50%      { border-color: rgba(99,179,237,0.8);  box-shadow: 0 0 14px rgba(99,179,237,0.2); }
}

h1 {
  font-size: clamp(1.8rem, 7vw, 3.6rem); font-weight: 800;
  line-height: 1.1; letter-spacing: -1px;
  background: linear-gradient(135deg, #e2e8f4 0%, #63b3ed 50%, #f6ad55 100%);
  background-size: 200% 200%;
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin-bottom: 14px; animation: gradient-shift 6s ease infinite; position: relative;
}
@keyframes gradient-shift { 0%,100%{background-position:0% 50%} 50%{background-position:100% 50%} }

.subtitle {
  font-size: clamp(13px, 2.5vw, 15px); color: var(--text-dim);
  line-height: 1.6; max-width: 560px; margin: 0 auto; position: relative;
}

/* ── Card ── */
.card {
  background: var(--bg2); border: 1px solid var(--border); border-radius: 20px;
  padding: clamp(20px, 4vw, 36px); margin-bottom: 24px;
  animation: fadeUp 0.7s ease both; position: relative; overflow: hidden;
  will-change: transform; transition: box-shadow 0.3s ease;
}
.card:nth-child(2){ animation-delay: 0.15s; }
.card:nth-child(3){ animation-delay: 0.30s; }
.card::after {
  content: ''; position: absolute; top: 0; left: -100%; width: 50%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.02), transparent);
  transform: skewX(-20deg); animation: card-sweep 6s ease-in-out infinite;
  pointer-events: none;
}
@keyframes card-sweep { 0%,70%{left:-100%} 100%{left:160%} }
.card:hover { box-shadow: 0 0 40px rgba(99,179,237,0.08), 0 8px 32px rgba(0,0,0,0.3); }

.card-label {
  font-family: 'Space Mono', monospace; font-size: 11px;
  letter-spacing: 2.5px; text-transform: uppercase; color: var(--text-dim); margin-bottom: 20px;
}

/* ── Class Selector ── */
.class-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }

.class-btn {
  background: var(--bg3); border: 1.5px solid var(--border); border-radius: var(--radius);
  padding: clamp(12px, 2.5vw, 18px) clamp(8px, 2vw, 12px);
  cursor: pointer; text-align: center; position: relative; overflow: hidden;
  transition: all 0.3s ease; width: 100%;
}
.class-btn::before {
  content: ''; position: absolute; inset: 0; opacity: 0;
  transition: opacity 0.25s ease; border-radius: var(--radius);
}
.class-btn::after {
  content: ''; position: absolute; top: -50%; left: -75%; width: 50%; height: 200%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.07), transparent);
  transform: skewX(-20deg); transition: left 0.5s ease;
}
.class-btn:hover::after { left: 125%; }
.class-btn.galaxy::before { background: var(--galaxy-glow); }
.class-btn.qso::before    { background: var(--qso-glow); }
.class-btn.star::before   { background: var(--star-glow); }
.class-btn:hover::before, .class-btn.active::before { opacity: 1; }
.class-btn.galaxy:hover, .class-btn.galaxy.active { border-color: var(--galaxy); box-shadow: 0 0 20px rgba(246,173,85,0.2); transform: translateY(-3px); }
.class-btn.qso:hover,    .class-btn.qso.active    { border-color: var(--qso);    box-shadow: 0 0 20px rgba(99,179,237,0.2);  transform: translateY(-3px); }
.class-btn.star:hover,   .class-btn.star.active   { border-color: var(--star);   box-shadow: 0 0 20px rgba(104,211,145,0.2); transform: translateY(-3px); }

.class-icon { font-size: clamp(22px, 4vw, 28px); display: block; margin-bottom: 8px; transition: transform 0.3s ease; position: relative; }
.class-btn:hover .class-icon { transform: scale(1.25) rotate(-8deg); }
.class-name { font-size: clamp(11px, 2vw, 13px); font-weight: 700; letter-spacing: 1px; display: block; position: relative; }
.class-btn.galaxy .class-name { color: var(--galaxy); }
.class-btn.qso    .class-name { color: var(--qso); }
.class-btn.star   .class-name { color: var(--star); }
.class-desc { font-size: clamp(9px, 1.8vw, 11px); color: var(--text-dim); margin-top: 4px; display: block; position: relative; font-family: 'Space Mono', monospace; }

/* ── Band Inputs ── */
.band-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: clamp(8px, 2vw, 12px); }
.band-field { display: flex; flex-direction: column; gap: 8px; min-width: 0; }

.band-label { font-family: 'Space Mono', monospace; font-size: clamp(9px, 1.8vw, 11px); letter-spacing: 2px; text-transform: uppercase; }
.band-label.u { color: #b794f4; }
.band-label.g { color: #68d391; }
.band-label.r { color: #fc8181; }
.band-label.i { color: #f6ad55; }
.band-label.z { color: #63b3ed; }
.band-wl { font-size: 10px; color: var(--text-dim); font-family: 'Space Mono', monospace; display: block; margin-top: -4px; }

input[type="number"] {
  background: var(--bg3); border: 1.5px solid var(--border); border-radius: 8px;
  color: var(--text); font-family: 'Space Mono', monospace;
  font-size: 16px;
  padding: clamp(8px, 2vw, 12px) clamp(6px, 1.5vw, 10px);
  width: 100%; outline: none; -moz-appearance: textfield; appearance: textfield;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; appearance: none; }
input[type="number"]:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(99,179,237,0.12);
}
.band-hint { font-size: 10px; color: var(--text-dim); font-family: 'Space Mono', monospace; }

/* ── Step 02 Mascot Header ── */
.step02-header {
  display: flex; align-items: flex-start;
  justify-content: space-between; margin-bottom: 24px; gap: 12px;
}
.mascot-wrap { display: flex; flex-direction: column; align-items: center; flex-shrink: 0; }
.mascot-bubble {
  background: var(--bg3); border: 1px solid var(--border-glow); border-radius: 100px;
  padding: 5px 12px; font-family: 'Space Mono', monospace; font-size: clamp(9px, 1.8vw, 10px);
  color: var(--qso); white-space: nowrap; margin-bottom: 4px; position: relative;
  animation: float 3s ease-in-out infinite;
}
.mascot-bubble::after {
  content: ''; position: absolute; bottom: -6px; left: 50%; transform: translateX(-50%);
  border-left: 5px solid transparent; border-right: 5px solid transparent;
  border-top: 6px solid var(--border-glow);
}

/* ── MASCOT IMAGE — GPU-accelerated ── */
.mascot-img {
  width: clamp(90px, 14vw, 140px);
  height: auto;
  image-rendering: auto;
  will-change: transform;
  transform-origin: center bottom;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

@keyframes float { 0%,100%{transform:translateY(0)} 50%{transform:translateY(-5px)} }

/* ── Predict Button ── */
.predict-btn {
  width: 100%; padding: clamp(12px, 2.5vw, 16px);
  background: linear-gradient(135deg, #1a3a5c, #0f2540);
  border: 1.5px solid var(--qso); border-radius: var(--radius);
  color: var(--qso); font-family: 'Syne', sans-serif;
  font-size: clamp(13px, 2.5vw, 15px); font-weight: 700; letter-spacing: 1.5px;
  text-transform: uppercase; cursor: pointer; margin-top: 8px;
  position: relative; overflow: hidden; transition: all 0.3s ease;
}
.predict-btn::before {
  content: ''; position: absolute; top: 0; left: -100%; width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(99,179,237,0.18), transparent);
  transition: left 0.6s ease;
}
.predict-btn:hover::before { left: 100%; }
.predict-btn:hover { box-shadow: 0 0 30px rgba(99,179,237,0.4), 0 4px 20px rgba(0,0,0,0.4); transform: translateY(-2px); }
.predict-btn:active { transform: translateY(0); }
@keyframes btn-blink { 50%{ opacity: 0.5; } }
.predict-btn.loading span { animation: btn-blink 0.7s step-end infinite; }

/* ── Result Panel ── */
#result-panel { display: none; animation: fadeUp 0.6s ease both; margin-bottom: 24px; }
.result-inner {
  background: var(--bg2); border: 1.5px solid var(--border-glow);
  border-radius: 20px; padding: clamp(20px, 4vw, 36px); position: relative; overflow: hidden;
}
.result-inner::before {
  content: ''; position: absolute; top: -60px; right: -60px;
  width: 200px; height: 200px; border-radius: 50%;
  background: radial-gradient(circle, rgba(99,179,237,0.1), transparent 70%);
  animation: glow-pulse 3s ease-in-out infinite; pointer-events: none;
}
.result-inner::after {
  content: ''; position: absolute; top: 0; left: -60%; width: 60%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(99,179,237,0.03), transparent);
  animation: scan-sweep 4s ease-in-out infinite; pointer-events: none;
}
@keyframes glow-pulse { 0%,100%{transform:scale(1);opacity:0.6} 50%{transform:scale(1.4);opacity:1} }
@keyframes scan-sweep { 0%{left:-60%} 100%{left:160%} }

.result-label { font-family: 'Space Mono', monospace; font-size: 11px; letter-spacing: 2.5px; text-transform: uppercase; color: var(--text-dim); margin-bottom: 8px; }
.result-value { font-family: 'Space Mono', monospace; font-size: clamp(2rem, 8vw, 4rem); font-weight: 700; letter-spacing: -1px; line-height: 1; margin-bottom: 6px; transition: color 0.4s ease; }
.result-unit  { font-size: clamp(11px, 2vw, 14px); color: var(--text-dim); font-family: 'Space Mono', monospace; margin-bottom: 20px; }

/* ══════════════════════════════════════
   95% CONFIDENCE INTERVAL BOX
══════════════════════════════════════ */
.ci-box {
  --ci-color: var(--qso);
  background: var(--bg3);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 14px;
  padding: 16px 18px;
  margin-bottom: 24px;
  animation: fadeUp 0.5s ease 0.15s both;
  transition: border-color 0.3s ease;
}
.ci-box:hover { border-color: var(--ci-color, var(--border-glow)); }

/* Header row: title + note */
.ci-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  flex-wrap: wrap;
  gap: 6px;
}
.ci-title {
  font-family: 'Space Mono', monospace;
  font-size: 10px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-dim);
}
.ci-note {
  font-family: 'Space Mono', monospace;
  font-size: 9px;
  letter-spacing: 1px;
  color: var(--ci-color, var(--qso));
  opacity: 0.75;
  background: rgba(99,179,237,0.07);
  border: 1px solid rgba(99,179,237,0.2);
  border-radius: 100px;
  padding: 2px 10px;
}

/* Main bar row: lower | track | upper */
.ci-bar-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

/* Bound blocks (left & right) */
.ci-bound-block {
  flex-shrink: 0;
  text-align: left;
  min-width: 72px;
}
.ci-bound-block-right { text-align: right; }
.ci-bound-label {
  font-family: 'Space Mono', monospace;
  font-size: 9px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 3px;
}
.ci-bound-value {
  font-family: 'Space Mono', monospace;
  font-size: clamp(11px, 2vw, 13px);
  font-weight: 700;
  color: var(--ci-color, var(--qso));
  overflow-wrap: break-word;
}

/* Track: the visual range bar */
.ci-track-wrap { flex: 1; min-width: 0; }
.ci-track {
  position: relative;
  height: 10px;
  border-radius: 100px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.08);
  overflow: visible;
  margin-bottom: 6px;
}

/* Filled region of the CI */
.ci-fill {
  position: absolute;
  top: 0; bottom: 0;
  border-radius: 100px;
  transition: left 0.4s ease, width 0.4s ease, background 0.4s ease;
}

/* Predicted value marker (dot in the centre) */
.ci-marker {
  position: absolute;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2.5px solid rgba(255,255,255,0.9);
  transition: left 0.4s ease, background 0.4s ease, box-shadow 0.4s ease;
  z-index: 2;
}

/* Axis labels below the track */
.ci-track-labels {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: 'Space Mono', monospace;
  font-size: 9px;
  color: var(--text-dim);
}
.ci-track-center-label {
  font-size: 8px;
  letter-spacing: 0.5px;
  opacity: 0.6;
  text-align: center;
}

/* Bottom row: width chip + interpretation */
.ci-width-row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 4px;
}
.ci-width-chip {
  font-family: 'Space Mono', monospace;
  font-size: 10px;
  font-weight: 700;
  color: var(--text-dim);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 100px;
  padding: 3px 12px;
  letter-spacing: 0.5px;
}
.ci-interp {
  font-family: 'Space Mono', monospace;
  font-size: 10px;
  line-height: 1.4;
  flex: 1;
}

/* Mobile: stack bound blocks vertically */
@media (max-width: 480px) {
  .ci-bar-row     { flex-wrap: wrap; }
  .ci-bound-block { min-width: auto; flex: 1; }
  .ci-track-wrap  { order: 3; width: 100%; }
}

/* ══════════════════════════════════════
   END CI BOX
══════════════════════════════════════ */

.result-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 24px; }
.result-stat { background: var(--bg3); border: 1px solid var(--border); border-radius: 10px; padding: clamp(10px, 2vw, 14px); transition: transform 0.2s ease, border-color 0.2s ease; min-width: 0; }
.result-stat:hover { transform: translateY(-2px); border-color: var(--border-glow); }
.stat-label { font-family: 'Space Mono', monospace; font-size: 10px; letter-spacing: 1.5px; color: var(--text-dim); text-transform: uppercase; margin-bottom: 6px; }
.stat-value { font-family: 'Space Mono', monospace; font-size: clamp(11px, 2vw, 14px); font-weight: 700; overflow-wrap: break-word; }

.equation-box { background: var(--bg3); border: 1px solid var(--border); border-radius: 10px; padding: 16px 20px; margin-bottom: 20px; transition: border-color 0.3s ease; overflow-x: auto; }
.equation-box:hover { border-color: var(--border-glow); }
.equation-title { font-family: 'Space Mono', monospace; font-size: 10px; letter-spacing: 2px; color: var(--text-dim); text-transform: uppercase; margin-bottom: 10px; }
.equation-text { font-family: 'Space Mono', monospace; font-size: clamp(10px, 1.8vw, 12px); line-height: 1.9; }
.eq-highlight { color: var(--qso); }

.warning-banner { display: flex; align-items: flex-start; gap: 10px; background: rgba(246,173,85,0.07); border: 1px solid rgba(246,173,85,0.3); border-radius: 10px; padding: 14px 16px; font-size: clamp(11px, 2vw, 13px); color: var(--galaxy); line-height: 1.5; animation: fadeUp 0.4s ease both; }
.warning-banner.good { background: rgba(104,211,145,0.07); border-color: rgba(104,211,145,0.3); color: var(--star); }

.error-msg { background: rgba(252,129,129,0.07); border: 1px solid rgba(252,129,129,0.3); border-radius: 10px; padding: 14px 16px; color: #fc8181; font-family: 'Space Mono', monospace; font-size: clamp(11px, 2vw, 13px); display: none; margin-top: 12px; animation: shake 0.4s ease both; }
@keyframes shake { 0%,100%{transform:translateX(0)} 20%{transform:translateX(-6px)} 40%{transform:translateX(6px)} 60%{transform:translateX(-4px)} 80%{transform:translateX(4px)} }

/* ── Simulation Canvases ── */
.sim-canvas { width: 100%; display: block; border-radius: 8px; min-height: 60px; }

/* ── Info Section ── */
.info-section { margin-top: 40px; animation: fadeUp 0.7s ease 0.3s both; }
.info-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.info-card { background: var(--bg2); border: 1px solid var(--border); border-radius: var(--radius); padding: clamp(14px, 3vw, 20px); transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease; }
.info-card:hover { transform: translateY(-5px); border-color: var(--border-glow); box-shadow: 0 10px 40px rgba(0,0,0,0.3); }
.info-card-title { font-size: 13px; font-weight: 700; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.info-card-body { font-size: clamp(10px, 1.8vw, 12px); color: var(--text-dim); line-height: 1.6; font-family: 'Space Mono', monospace; }
.r2-bar-wrap { margin-top: 8px; height: 4px; background: var(--border); border-radius: 100px; overflow: hidden; }
.r2-bar { height: 100%; border-radius: 100px; width: 0; transition: width 1.6s cubic-bezier(0.25,1,0.5,1); }

footer { text-align: center; margin-top: 60px; padding-top: 24px; border-top: 1px solid var(--border); color: var(--text-dim); font-family: 'Space Mono', monospace; font-size: clamp(9px, 1.8vw, 11px); letter-spacing: 1px; line-height: 2; animation: fadeUp 0.7s ease 0.4s both; }
footer a { color: var(--qso); text-decoration: none; }
footer a:hover { text-decoration: underline; }

@keyframes fadeDown { from{opacity:0;transform:translateY(-24px)} to{opacity:1;transform:translateY(0)} }
@keyframes fadeUp   { from{opacity:0;transform:translateY(24px)}  to{opacity:1;transform:translateY(0)} }

/* ══════════════════════════════════════
   RESPONSIVE BREAKPOINTS
══════════════════════════════════════ */

@media (max-width: 768px) {
  .result-grid   { grid-template-columns: repeat(2, 1fr); }
  .info-grid     { grid-template-columns: repeat(2, 1fr); }
  #cosmic-stats  { grid-template-columns: repeat(2, 1fr) !important; }
  .band-grid     { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 600px) {
  .class-grid    { grid-template-columns: repeat(3, 1fr); gap: 8px; }
  .band-grid     { grid-template-columns: repeat(3, 1fr); }
  .result-grid   { grid-template-columns: repeat(2, 1fr); }
  .info-grid     { grid-template-columns: 1fr; }
  #cosmic-stats  { grid-template-columns: 1fr !important; }
  .orbit-ring, .orbit-ring-2 { display: none; }

  .step02-header { flex-wrap: wrap; }
  .mascot-wrap   { order: -1; width: 100%; flex-direction: row; align-items: center; gap: 10px; margin-bottom: 8px; }
  .mascot-bubble { margin-bottom: 0; }
  .mascot-img    { width: 72px; }
  .equation-text { font-size: 10px; }
}

/* ── Doppler Slider ── */
#doppler-slider {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 8px; border-radius: 100px;
  background: linear-gradient(90deg, #dc2200 0%, #550000 50%, #0a0000 100%);
  outline: none; cursor: pointer;
  border: 1px solid rgba(255,255,255,0.15);
  box-shadow: 0 0 8px rgba(0,0,0,0.4);
}
#doppler-slider::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 20px; height: 20px; border-radius: 50%;
  background: #fff; border: 2.5px solid #fff;
  box-shadow: 0 0 12px rgba(255,255,255,0.7), 0 0 4px rgba(0,0,0,0.5);
  cursor: grab; transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}
#doppler-slider::-webkit-slider-thumb:active { transform: scale(1.3); cursor: grabbing; }
#doppler-slider::-moz-range-thumb {
  width: 20px; height: 20px; border-radius: 50%; background: #fff;
  border: 2.5px solid #fff;
  box-shadow: 0 0 12px rgba(255,255,255,0.7); cursor: grab;
}

@media (max-width: 400px) {
  .class-grid { grid-template-columns: 1fr; }
  .band-grid  { grid-template-columns: repeat(2, 1fr); }
  .card       { border-radius: 14px; }
}