/* ===== MD3 Design Tokens ===== */
:root {
  --md-primary: #12664f;
  --md-on-primary: #ffffff;
  --md-primary-container: #a4f2ce;
  --md-on-primary-container: #002116;

  --md-surface: #fbf8fd;
  --md-on-surface: #1c1b1f;
  --md-on-surface-variant: #49454f;
  --md-surface-container-lowest: #ffffff;
  --md-surface-container-low: #f7f2fa;
  --md-surface-container: #f1ecf4;
  --md-surface-container-high: #ece6f0;
  --md-surface-container-highest: #e6e0e9;
  --md-outline: #79747e;
  --md-outline-variant: #cac4d0;

  --md-elevation-1: 0 1px 2px rgba(0,0,0,.3), 0 1px 3px 1px rgba(0,0,0,.15);
  --md-elevation-2: 0 1px 2px rgba(0,0,0,.3), 0 2px 6px 2px rgba(0,0,0,.15);
  --md-elevation-3: 0 4px 8px 3px rgba(0,0,0,.15), 0 1px 3px rgba(0,0,0,.3);

  --md-shape-corner-xs: 4px;
  --md-shape-corner-sm: 8px;
  --md-shape-corner-md: 12px;
  --md-shape-corner-lg: 16px;
  --md-shape-corner-xl: 28px;
  --md-shape-corner-full: 9999px;

  color-scheme: light dark;
}

/* ===== Dark mode: system preference ===== */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --md-primary: #3dcc9a;
    --md-on-primary: #003828;
    --md-primary-container: #005139;
    --md-on-primary-container: #a4f2ce;

    --md-surface: #141218;
    --md-on-surface: #e6e0e9;
    --md-on-surface-variant: #cac4d0;
    --md-surface-container-lowest: #0f0d13;
    --md-surface-container-low: #1c1b1f;
    --md-surface-container: #211f26;
    --md-surface-container-high: #2b2930;
    --md-surface-container-highest: #36343b;
    --md-outline: #938f99;
    --md-outline-variant: #49454f;

    --md-elevation-1: 0 1px 3px 1px rgba(0,0,0,.4), 0 1px 2px rgba(0,0,0,.6);
    --md-elevation-2: 0 2px 6px 2px rgba(0,0,0,.4), 0 1px 2px rgba(0,0,0,.6);
    --md-elevation-3: 0 4px 8px 3px rgba(0,0,0,.4), 0 1px 3px rgba(0,0,0,.6);
  }
}

/* ===== Dark mode: manual override ===== */
[data-theme="dark"] {
  --md-primary: #3dcc9a;
  --md-on-primary: #003828;
  --md-primary-container: #005139;
  --md-on-primary-container: #a4f2ce;

  --md-surface: #141218;
  --md-on-surface: #e6e0e9;
  --md-on-surface-variant: #cac4d0;
  --md-surface-container-lowest: #0f0d13;
  --md-surface-container-low: #1c1b1f;
  --md-surface-container: #211f26;
  --md-surface-container-high: #2b2930;
  --md-surface-container-highest: #36343b;
  --md-outline: #938f99;
  --md-outline-variant: #49454f;

  --md-elevation-1: 0 1px 3px 1px rgba(0,0,0,.4), 0 1px 2px rgba(0,0,0,.6);
  --md-elevation-2: 0 2px 6px 2px rgba(0,0,0,.4), 0 1px 2px rgba(0,0,0,.6);
  --md-elevation-3: 0 4px 8px 3px rgba(0,0,0,.4), 0 1px 3px rgba(0,0,0,.6);
}

/* ===== Light mode: manual override ===== */
[data-theme="light"] {
  --md-primary: #12664f;
  --md-on-primary: #ffffff;
  --md-primary-container: #a4f2ce;
  --md-on-primary-container: #002116;

  --md-surface: #fbf8fd;
  --md-on-surface: #1c1b1f;
  --md-on-surface-variant: #49454f;
  --md-surface-container-lowest: #ffffff;
  --md-surface-container-low: #f7f2fa;
  --md-surface-container: #f1ecf4;
  --md-surface-container-high: #ece6f0;
  --md-surface-container-highest: #e6e0e9;
  --md-outline: #79747e;
  --md-outline-variant: #cac4d0;

  --md-elevation-1: 0 1px 2px rgba(0,0,0,.3), 0 1px 3px 1px rgba(0,0,0,.15);
  --md-elevation-2: 0 1px 2px rgba(0,0,0,.3), 0 2px 6px 2px rgba(0,0,0,.15);
  --md-elevation-3: 0 4px 8px 3px rgba(0,0,0,.15), 0 1px 3px rgba(0,0,0,.3);
}

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

/* ===== Typography ===== */
body {
  font-family: "Noto Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  color: var(--md-on-surface);
  background: var(--md-surface);
  min-height: 100vh;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ===== Top App Bar ===== */
.top-bar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  padding: 0 16px;
  background: var(--md-surface);
  border-bottom: 1px solid var(--md-outline-variant);
}

.top-bar-title {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--md-on-surface);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.top-bar-actions {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

/* ===== Icon Buttons ===== */
.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: var(--md-shape-corner-full);
  background: transparent;
  color: var(--md-on-surface-variant);
  cursor: pointer;
  font-size: 1.25rem;
  position: relative;
  overflow: hidden;
  transition: background 200ms;
}

.github-link {
  text-decoration: none;
}

.icon-btn:hover {
  background: rgba(28, 27, 31, 0.08);
}

.icon-btn:active {
  background: rgba(28, 27, 31, 0.12);
}

[data-theme="dark"] .icon-btn:hover {
  background: rgba(230, 224, 233, 0.08);
}

[data-theme="dark"] .icon-btn:active {
  background: rgba(230, 224, 233, 0.12);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-btn:hover {
    background: rgba(230, 224, 233, 0.08);
  }
  :root:not([data-theme="light"]) .icon-btn:active {
    background: rgba(230, 224, 233, 0.12);
  }
}

/* ===== Lang Toggle ===== */
.lang-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 32px;
  padding: 0 12px;
  border: 1px solid var(--md-outline);
  border-radius: var(--md-shape-corner-sm);
  background: transparent;
  color: var(--md-on-surface-variant);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background 200ms;
}

.lang-btn:hover {
  background: var(--md-surface-container-high);
}

/* ===== Main Layout ===== */
main {
  width: min(1080px, 100% - 32px);
  margin: 0 auto;
  padding: 32px 0 64px;
}

/* ===== Hero ===== */
.hero {
  padding: 24px 0 40px;
}

.hero-eyebrow {
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--md-primary);
  margin-bottom: 12px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 400;
  line-height: 1.12;
  color: var(--md-on-surface);
  margin-bottom: 16px;
}

.hero-lead {
  max-width: 680px;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--md-on-surface-variant);
  margin-bottom: 24px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.install-hint {
  margin-top: 14px;
  color: var(--md-on-surface-variant);
  font-size: 0.875rem;
  line-height: 1.6;
}

.install-guide {
  margin-top: 18px;
  max-width: 720px;
  padding: 20px 24px;
  border-radius: var(--md-shape-corner-lg);
  background: var(--md-surface-container-low);
  border: 1px solid var(--md-outline-variant);
  box-shadow: var(--md-elevation-1);
  outline: none;
}

.install-guide-eyebrow {
  color: var(--md-primary);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.install-guide-title {
  margin-top: 8px;
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--md-on-surface);
}

.install-guide-body,
.install-guide-note {
  margin-top: 12px;
  color: var(--md-on-surface-variant);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.install-guide-steps {
  margin-top: 14px;
  padding-left: 20px;
  color: var(--md-on-surface);
  font-size: 0.9375rem;
  line-height: 1.8;
}

/* ===== Buttons ===== */
.btn-filled {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 40px;
  padding: 0 24px;
  border: none;
  border-radius: var(--md-shape-corner-full);
  background: var(--md-primary);
  color: var(--md-on-primary);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: box-shadow 200ms, transform 160ms;
}

.btn-filled:hover {
  box-shadow: var(--md-elevation-1);
}

.btn-filled:active {
  transform: scale(0.98);
}

.btn-tonal {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 40px;
  padding: 0 24px;
  border: none;
  border-radius: var(--md-shape-corner-full);
  background: var(--md-surface-container-high);
  color: var(--md-on-surface);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: box-shadow 200ms, transform 160ms;
}

.btn-tonal:hover {
  box-shadow: var(--md-elevation-1);
}

.btn-tonal:active {
  transform: scale(0.98);
}

/* ===== Section ===== */
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

.section-header h2 {
  font-size: 1.375rem;
  font-weight: 400;
  color: var(--md-on-surface);
}

.section-chip {
  display: inline-flex;
  align-items: center;
  height: 32px;
  padding: 0 16px;
  border-radius: var(--md-shape-corner-sm);
  background: var(--md-surface-container-high);
  color: var(--md-on-surface-variant);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.section-desc {
  color: var(--md-on-surface-variant);
  font-size: 0.875rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

/* ===== Portal Grid ===== */
.portal-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

/* ===== Portal Card (MD3 Filled Card) ===== */
.portal-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 24px 16px;
  border-radius: var(--md-shape-corner-md);
  background: var(--md-surface-container-low);
  color: inherit;
  text-decoration: none;
  position: relative;
  overflow: hidden;
  text-align: center;
  border: none;
  width: 100%;
  font: inherit;
  transition: box-shadow 200ms, transform 200ms;
}

.portal-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--md-on-surface);
  opacity: 0;
  transition: opacity 200ms;
  pointer-events: none;
}

.portal-card:hover::before {
  opacity: 0.08;
}

.portal-card:active::before {
  opacity: 0.12;
}

.portal-card:hover {
  box-shadow: var(--md-elevation-2);
  transform: translateY(-2px);
}

.portal-card.featured {
  background: var(--md-primary-container);
  color: var(--md-on-primary-container);
}

.portal-card.featured .portal-icon {
  color: var(--md-on-primary-container);
}


.portal-icon {
  width: 32px;
  height: 32px;
  color: var(--md-primary);
  flex-shrink: 0;
}

.portal-card h3 {
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1.3;
}

/* ===== Usage Notes Card ===== */
.compliance-card {
  margin-top: 24px;
  padding: 20px 24px;
  border-radius: var(--md-shape-corner-md);
  background: var(--md-surface-container);
  border: 1px solid var(--md-outline-variant);
}

.compliance-card h2 {
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: 12px;
}

.compliance-card ul {
  padding-left: 20px;
  color: var(--md-on-surface-variant);
  font-size: 0.875rem;
  line-height: 1.8;
}

/* ===== Footer ===== */
.footer {
  margin-top: 48px;
  padding-top: 16px;
  border-top: 1px solid var(--md-outline-variant);
  text-align: center;
  font-size: 0.75rem;
  color: var(--md-outline);
}

.footer a {
  color: var(--md-primary);
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .portal-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  main {
    width: calc(100% - 24px);
  }

  .top-bar {
    padding: 0 12px;
  }

  .hero {
    padding: 16px 0 28px;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .install-guide {
    padding: 18px;
  }

  .portal-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .portal-card {
    min-height: auto;
  }

  .section-header {
    flex-direction: column;
    gap: 8px;
  }
}

/* ===== Utility ===== */
[hidden] {
  display: none !important;
}