/* Shared layout — modern, minimal */
:root {
  --bg0: #f4f6f8;
  --bg1: #e8ecf1;
  --ink: #0d1117;
  --muted: #5c6570;
  --line: rgba(13, 17, 23, 0.08);
  --accent: #1a56c4;
  --accent-soft: rgba(26, 86, 196, 0.1);
  --card: #ffffff;
  --radius-lg: 20px;
  --radius-md: 12px;
  --shadow: 0 24px 48px rgba(13, 17, 23, 0.06);
  --shadow-hover: 0 32px 64px rgba(13, 17, 23, 0.1);
  --font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

/* Screen-reader-only utility */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg0);
  line-height: 1.5;
}

/* Optional hero background image (部署时放入 static/img） */
body.has-hero-bg {
  background-color: var(--bg0);
  background-image:
    radial-gradient(1200px 600px at 10% -10%, rgba(26, 86, 196, 0.09), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(13, 110, 90, 0.07), transparent 50%),
    linear-gradient(180deg, var(--bg0) 0%, var(--bg1) 100%);
}

.site-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding: clamp(1.25rem, 4vw, 2.5rem) 1.25rem 2rem;
}

.site-header {
  width: 100%;
  max-width: 1080px;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-brand {
  font-size: clamp(1.35rem, 2.5vw, 1.65rem);
  font-weight: 650;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.site-brand span {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.82rem;
  font-weight: 400;
  color: var(--muted);
  letter-spacing: 0;
}

.back-link {
  font-size: 0.875rem;
  color: var(--accent);
  text-decoration: none;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--accent-soft);
  transition: background 0.15s, transform 0.12s;
}

.back-link:hover {
  background: rgba(26, 86, 196, 0.16);
  transform: translateY(-1px);
}

.site-main {
  width: 100%;
  max-width: 1080px;
}

.hero-card {
  background: var(--card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  padding: clamp(1.35rem, 3vw, 2rem);
  margin-bottom: 1.75rem;
}

.hero-card h1 {
  margin: 0 0 0.35rem;
  font-size: clamp(1.5rem, 3vw, 1.85rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.hero-card .lead {
  margin: 0 0 1.25rem;
  color: var(--muted);
  font-size: 0.95rem;
  max-width: 42rem;
}

.section-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin: 0 0 0.65rem;
  font-weight: 600;
}

.nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0.85rem;
}

.nav-tile {
  display: block;
  text-decoration: none;
  color: inherit;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  transition: border-color 0.15s, box-shadow 0.2s, transform 0.12s;
}

.nav-tile:hover {
  border-color: rgba(26, 86, 196, 0.25);
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.nav-tile .t {
  font-weight: 650;
  font-size: 0.98rem;
  color: var(--ink);
}

.nav-tile .d {
  margin-top: 0.35rem;
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.45;
}

.site-foot {
  margin-top: 2rem;
  font-size: 0.78rem;
  color: var(--muted);
  text-align: center;
}

.site-foot code {
  font-size: 0.85em;
  background: rgba(13, 17, 23, 0.06);
  padding: 0.12rem 0.35rem;
  border-radius: 6px;
}

/* Tool pages */
.tool-panel {
  background: var(--card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  padding: clamp(1.25rem, 3vw, 1.75rem);
  max-width: 520px;
  margin: 0 auto;
}

.tool-panel h1 {
  margin: 0 0 0.25rem;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.tool-panel .hint {
  margin: 0 0 1.25rem;
  font-size: 0.85rem;
  color: var(--muted);
}

.field-row {
  display: grid;
  gap: 0.65rem;
  margin-bottom: 1rem;
}

.field-row label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
}

.field-row input,
.field-row select {
  width: 100%;
  font: inherit;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fafbfc;
}

.field-row input:focus,
.field-row select:focus {
  outline: 2px solid rgba(26, 86, 196, 0.35);
  outline-offset: 0;
  border-color: var(--accent);
  background: #fff;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.25rem;
}

button.primary {
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  border: none;
  border-radius: 10px;
  padding: 0.55rem 1.1rem;
  background: var(--accent);
  color: #fff;
}

button.primary:hover {
  filter: brightness(1.05);
}

.result-box {
  margin-top: 1.1rem;
  padding: 0.9rem 1rem;
  border-radius: var(--radius-md);
  background: var(--accent-soft);
  border: 1px solid rgba(26, 86, 196, 0.15);
  font-size: 0.9rem;
}

.result-box strong {
  display: block;
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

/* Calculator keypad */
.calc-display {
  width: 100%;
  min-height: 3.8rem;
  font: inherit;
  font-size: clamp(1.35rem, 5vw, 2rem);
  font-weight: 600;
  text-align: right;
  padding: 0.75rem 0.9rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: #0d1117;
  color: #f0f3f6;
  letter-spacing: 0.02em;
  margin-bottom: 0.75rem;
  overflow-x: auto;
  overflow-y: hidden;
  white-space: nowrap;
  scrollbar-width: thin;
  scrollbar-color: rgba(240, 243, 246, 0.2) transparent;
  line-height: 1.3;
  transition: font-size 0.1s ease;
}

.calc-display::-webkit-scrollbar {
  height: 3px;
}
.calc-display::-webkit-scrollbar-thumb {
  background: rgba(240, 243, 246, 0.25);
  border-radius: 3px;
}

.calc-display.calc-error {
  color: #f87171;
  font-size: 1rem;
}

.calc-keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.4rem;
}

.calc-keys button {
  font: inherit;
  font-size: 1.05rem;
  font-weight: 500;
  padding: 0.7rem 0;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  transition: background 0.1s, transform 0.1s, box-shadow 0.1s;
  position: relative;
  overflow: hidden;
}

.calc-keys button:hover {
  background: #f0f2f5;
  z-index: 1;
}

.calc-keys button:active,
.calc-keys button.key-active {
  background: #e2e6ec;
  transform: scale(0.94);
  box-shadow: 0 0 0 2px rgba(26, 86, 196, 0.2);
  z-index: 2;
}

.calc-keys button.op {
  background: #eef2f8;
  font-weight: 600;
}

.calc-keys button.op:active,
.calc-keys button.op.key-active {
  background: #d6dce8;
}

.calc-keys button.op-eq {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  font-weight: 700;
}

.calc-keys button.op-eq:hover {
  filter: brightness(1.08);
}

.calc-keys button.op-eq:active,
.calc-keys button.op-eq.key-active {
  filter: brightness(0.92);
  transform: scale(0.94);
}

.calc-keys button.op-fn {
  background: #dce3ed;
  font-weight: 500;
  font-size: 0.9rem;
  color: #3a4555;
}

.calc-keys button.op-fn:active,
.calc-keys button.op-fn.key-active {
  background: #c8d2de;
}

.calc-keys button.wide {
  grid-column: span 2;
}

.mortgage-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.78rem;
  margin-top: 0.75rem;
}

.mortgage-table th,
.mortgage-table td {
  border-bottom: 1px solid var(--line);
  padding: 0.35rem 0.4rem;
  text-align: right;
}

.mortgage-table th:first-child,
.mortgage-table td:first-child {
  text-align: left;
}

.mortgage-scroll {
  max-height: 220px;
  overflow: auto;
  margin-top: 0.5rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
}

/* Dino jump game */
.game-shell {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(260px, 1fr);
  gap: 1rem;
  align-items: start;
}

.game-panel,
.rank-panel {
  background: var(--card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  padding: 1rem;
}

.game-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.score-badge {
  font-size: 0.8rem;
  color: var(--muted);
  background: #f3f6fb;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.25rem 0.65rem;
}

.game-canvas {
  width: 100%;
  display: block;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: linear-gradient(180deg, #f8fbff 0%, #ecf3ff 100%);
}

.game-help {
  margin: 0.65rem 0 0;
  font-size: 0.8rem;
  color: var(--muted);
}

.rank-panel h2 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}

.name-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.name-row input {
  font: inherit;
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fafbfc;
}

.skin-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
}

.skin-row select {
  font: inherit;
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fafbfc;
}

.rank-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

.rank-table th,
.rank-table td {
  padding: 0.38rem 0.2rem;
  border-bottom: 1px solid var(--line);
  text-align: right;
}

.rank-table th:first-child,
.rank-table td:first-child,
.rank-table th:nth-child(2),
.rank-table td:nth-child(2) {
  text-align: left;
}

@media (max-width: 900px) {
  .game-shell {
    grid-template-columns: 1fr;
  }
}