html {
  scroll-behavior: smooth;
  -webkit-tap-highlight-color: transparent;
}

:root {
  /* MD3 Light Theme */
  --md-sys-color-primary: #0d3e91;
  --md-sys-color-on-primary: #ffffff;
  --md-sys-color-primary-container: #d8e2ff;
  --md-sys-color-on-primary-container: #001a41;
  --md-sys-color-secondary: #a11a2b;
  --md-sys-color-on-secondary: #ffffff;
  --md-sys-color-secondary-container: #ffd9dd;
  --md-sys-color-on-secondary-container: #410008;
  --md-sys-color-surface: #fdfbff;
  --md-sys-color-on-surface: #1a1b1f;
  --md-sys-color-surface-variant: #e1e2ec;
  --md-sys-color-on-surface-variant: #44474f;
  --md-sys-color-surface-container-lowest: #ffffff;
  --md-sys-color-surface-container-low: #f4f3f7;
  --md-sys-color-surface-container: #eeedf1;
  --md-sys-color-surface-container-high: #e8e7eb;
  --md-sys-color-surface-container-highest: #e2e2e6;
  --md-sys-color-outline: #74777f;
  --md-sys-color-outline-variant: #c4c6d0;

  /* Easing */
  --md-sys-motion-easing-emphasized: cubic-bezier(0.2, 0, 0, 1);

  /* Legacy Maps */
  --whu-blue: var(--md-sys-color-primary);
  --whu-blue-deep: #072b67;
  --whu-blue-soft: #3f63af;
  --whu-red: var(--md-sys-color-secondary);
  --paper: var(--md-sys-color-surface);
  --surface: var(--md-sys-color-surface-container-lowest);
  --ink: var(--md-sys-color-on-surface);
  --ink-muted: var(--md-sys-color-on-surface-variant);
  --line: var(--md-sys-color-outline-variant);
  --card-bg: var(--md-sys-color-surface-container-highest);
  --card-head-bg: var(--md-sys-color-surface-container-high);

  --ease-out-quart: var(--md-sys-motion-easing-emphasized);
  --ease-out-expo: var(--md-sys-motion-easing-emphasized);
}

@media (prefers-color-scheme: dark) {
  :root {
    /* MD3 Dark Theme */
    --md-sys-color-primary: #aec6ff;
    --md-sys-color-on-primary: #002e69;
    --md-sys-color-primary-container: #004494;
    --md-sys-color-on-primary-container: #d8e2ff;
    --md-sys-color-secondary: #ffb3ba;
    --md-sys-color-on-secondary: #650012;
    --md-sys-color-secondary-container: #83001c;
    --md-sys-color-on-secondary-container: #ffd9dd;
    --md-sys-color-surface: #111318;
    --md-sys-color-on-surface: #e2e2e9;
    --md-sys-color-surface-variant: #44474f;
    --md-sys-color-on-surface-variant: #c4c6d0;
    --md-sys-color-surface-container-lowest: #0c0e13;
    --md-sys-color-surface-container-low: #1a1b20;
    --md-sys-color-surface-container: #1e1f25;
    --md-sys-color-surface-container-high: #282a2f;
    --md-sys-color-surface-container-highest: #33353a;
    --md-sys-color-outline: #8e9099;
    --md-sys-color-outline-variant: #44474f;

    --whu-blue-deep: #21438a;
    --whu-blue-soft: #7ca8f5;
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family:
    "Roboto", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.6;
}

.hero {
  min-height: 100vh;
  padding: clamp(20px, 4vw, 42px);
  color: #f2f6ff;
  background:
    linear-gradient(146deg, rgba(8, 45, 110, 0.9), rgba(12, 63, 148, 0.86)),
    url("./whu-library-side.jpg") center / cover no-repeat;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.14),
    transparent 46%
  );
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 55%, rgba(7, 34, 85, 0.75));
  pointer-events: none;
}

#sakura-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  pointer-events: none;
}

.hero-top {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.brand,
.hero-link {
  border: none;
  background: rgba(255, 255, 255, 0.1);
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 9999px;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.hero-link {
  color: #f2f6ff;
  text-decoration: none;
  transition: background-color 220ms var(--ease-out-quart);
}

.hero-link:hover,
.hero-link:focus-visible {
  background: rgba(242, 246, 255, 0.2);
  outline: none;
}

.hero-main {
  position: relative;
  z-index: 2;
  margin-top: clamp(40px, 11vh, 120px);
}

.hero-title {
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: clamp(2.8rem, 11vw, 8rem);
  line-height: 0.9;
  letter-spacing: -0.02em;
}

.hero-line {
  display: block;
  opacity: 0;
  transform: translateY(30px);
  animation: lineIn 900ms var(--ease-out-expo) forwards;
}

.hero-line:nth-child(2) {
  animation-delay: 120ms;
}

.hero-note {
  margin-top: 16px;
  max-width: 520px;
  font-size: 1rem;
  opacity: 0.95;
}

.page {
  max-width: 1220px;
  margin: 0 auto;
  background: var(--md-sys-color-surface);
  position: relative;
}

.section {
  padding: clamp(32px, 5vw, 64px) clamp(24px, 4vw, 42px);
}

.section.compact {
  padding-top: clamp(20px, 3vw, 32px);
  padding-bottom: clamp(20px, 3vw, 32px);
}

.section.compact .section-title {
  font-size: clamp(1.7rem, 4.2vw, 2.8rem);
}

.section-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: clamp(18px, 3vw, 44px);
}

.section-kicker {
  font-size: 0.82rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--whu-blue);
}

.section-title {
  margin-top: 6px;
  font-size: clamp(2rem, 5vw, 3.6rem);
  line-height: 0.95;
}

.section-copy {
  color: var(--ink-muted);
  max-width: 760px;
  font-size: 0.98rem;
}

@media (min-width: 901px) {
  .section-copy {
    text-align: right;
    margin-left: auto;
  }
}

.download-panel {
  background: var(--md-sys-color-surface-container-low);
  border-radius: 16px;
  overflow: hidden;
  border: none;
  box-shadow: none;
  transition:
    box-shadow 300ms var(--ease-out-quart),
    transform 300ms var(--ease-out-quart);
}

.tutorial-card {
  background: var(--md-sys-color-surface-container-highest);
  border-radius: 16px;
  overflow: hidden;
  border: none;
  transition:
    background-color 300ms var(--ease-out-expo),
    transform 300ms var(--ease-out-expo),
    box-shadow 300ms var(--ease-out-expo);
}

.tutorial-card:hover {
  background: var(--md-sys-color-surface-container);
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.1);
}

.download-panel {
  margin-top: 16px;
  transition: box-shadow 250ms var(--ease-out-quart);
}

.download-panel:hover {
  box-shadow:
    0 1px 3px 1px rgba(0, 0, 0, 0.08),
    0 1px 2px 0 rgba(0, 0, 0, 0.1);
}

.download-head,
.tutorial-head {
  padding: 16px;
  background: transparent;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  padding: 0 16px 16px;
}

.download-card {
  text-decoration: none;
  color: var(--md-sys-color-on-surface);
  background: var(--md-sys-color-surface-container-highest);
  border-radius: 12px;
  border: none;
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  transition:
    background-color 300ms var(--ease-out-expo),
    color 300ms var(--ease-out-expo),
    box-shadow 300ms var(--ease-out-expo),
    transform 300ms var(--ease-out-expo);
  min-height: 72px;
  transition:
    transform 300ms var(--ease-out-expo),
    background-color 300ms var(--ease-out-quart),
    color 300ms var(--ease-out-quart),
    box-shadow 300ms var(--ease-out-quart);
}

.download-card:hover,
.download-card:focus-visible {
  background: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
  outline: none;
}

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

.download-card.secondary {
  background: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
}

.download-title {
  font-weight: 600;
}

.download-description {
  font-size: 0.9rem;
  opacity: 0.88;
}

.tutorial-grid {
  margin-top: 16px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 12px;
}

.tutorial-body {
  padding: 0 16px 16px;
}

.tutorial-body ol {
  margin-left: 17px;
  color: var(--ink-muted);
}

.tutorial-body li + li {
  margin-top: 6px;
}

.tutorial-shot {
  margin-top: 12px;
  border-radius: 8px;
  border: 1px solid var(--md-sys-color-outline-variant);
  width: 100%;
}

.tutorial-link {
  display: inline-block;
  margin-top: 10px;
  color: var(--whu-blue);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;

  padding: clamp(30px, 4vw, 40px) clamp(24px, 4vw, 42px);
  background: var(--md-sys-color-surface-container);
  width: 100%;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.footer a {
  color: var(--md-sys-color-on-surface-variant);
  text-decoration: none;
  border: none;
  border-radius: 9999px;
  padding: 8px 16px;
  font-weight: 500;
  transition:
    background-color 200ms var(--ease-out-quart),
    color 200ms var(--ease-out-quart);
}

.footer a:hover,
.footer a:focus-visible {
  background: var(--md-sys-color-surface-variant);
  color: var(--md-sys-color-on-surface);
  outline: none;
}

.credits {
  margin-top: 12px;
  color: var(--ink-muted);
  font-size: 0.92rem;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(26px);
  transition:
    opacity 760ms var(--ease-out-expo),
    transform 760ms var(--ease-out-expo);
  transition-delay: var(--delay, 0ms);
}

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

@keyframes lineIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 900px) {
  .page {
    border-left: 0;
    border-right: 0;
  }

  .section-grid {
    grid-template-columns: 1fr;
  }

  .tutorial-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 767px) {
  .hero {
    min-height: 88vh;
    padding: 16px;
    background:
      linear-gradient(146deg, rgba(8, 45, 110, 0.9), rgba(12, 63, 148, 0.86)),
      url("./whu-cherry-castle.jpg") center / cover no-repeat;
  }

  .hero-top {
    align-items: flex-start;
  }

  .brand,
  .hero-link {
    font-size: 0.85rem;
    padding: 8px 14px;
  }

  .hero-main {
    margin-top: 54px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .hero-title {
    font-size: clamp(2.2rem, 14vw, 3.6rem);
    line-height: 0.92;
  }

  .hero-note {
    font-size: 0.95rem;
    margin: 16px auto 0;
  }

  .section {
    padding: 20px 14px;
  }

  .section-title {
    font-size: clamp(1.8rem, 9.2vw, 2.2rem);
  }

  .download-grid,
  .tutorial-grid {
    grid-template-columns: 1fr;
  }

  .download-card {
    padding: 14px;
    border-right: 0;
  }

  .tutorial-head,
  .download-head {
    min-height: 50px;
    padding: 11px 12px;
  }

  .tutorial-body {
    padding: 12px;
  }

  .footer {
    padding: 18px 14px 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  [data-reveal],
  .hero-line {
    opacity: 1;
    transform: none;
    animation: none;
  }
}
.calendar-embed-container {
  position: relative;
  overflow: hidden;
  width: 100%;
  padding-top: 75%;
  background: var(--md-sys-color-surface-container-highest);
  margin-top: 16px;
  border-radius: 16px;
  border: none;
  box-shadow: none;
  transition:
    box-shadow 300ms var(--ease-out-quart),
    transform 300ms var(--ease-out-quart);
}
.calendar-embed-container:hover {
  box-shadow:
    0 1px 3px 1px rgba(0, 0, 0, 0.08),
    0 1px 2px 0 rgba(0, 0, 0, 0.1);
}
.calendar-embed-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  width: 100%;
  height: 100%;
  border: none;
}
@media (min-width: 901px) {
  .calendar-embed-container {
    padding-top: 60%;
  }
}

.delay-50 {
  --delay: 50ms;
}
.delay-60 {
  --delay: 60ms;
}
.delay-80 {
  --delay: 80ms;
}
.delay-100 {
  --delay: 100ms;
}
.delay-120 {
  --delay: 120ms;
}
.delay-130 {
  --delay: 130ms;
}
.delay-160 {
  --delay: 160ms;
}
.delay-190 {
  --delay: 190ms;
}

.code-block {
  word-break: break-all;
  font-size: 0.85em;
  -webkit-user-select: all;
  user-select: all;
  background: var(--md-sys-color-surface-container);
  padding: 4px;
  border-radius: 4px;
  margin-top: 6px;
}

.tutorial-link.inline-link {
  margin-top: 0;
  display: inline;
}

.calendar-fallback {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--md-sys-color-surface-container-highest);
  color: var(--md-sys-color-on-surface-variant);
  padding: 24px;
}
.calendar-fallback h3 {
  margin-bottom: 8px;
  color: var(--md-sys-color-on-surface);
}
.calendar-embed-container.is-offline iframe {
  display: none;
}
.calendar-embed-container.is-offline .calendar-fallback {
  display: flex;
}

/* --- MD3 Buttons --- */
.hero-actions {
  display: flex;
  gap: 16px;
  margin-top: 32px;
  justify-content: flex-start;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 9999px;
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  transition:
    background-color 300ms var(--ease-out-expo),
    transform 300ms var(--ease-out-expo),
    box-shadow 300ms var(--ease-out-expo);
  border: none;
  cursor: pointer;
  letter-spacing: 0.5px;
}

.btn-primary {
  background: #d8e2ff;
  color: #001a41;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
  transform: translateY(-2px);
  background: #ecf0ff;
  outline: none;
}

.btn-tonal {
  background: rgba(255, 255, 255, 0.15);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-tonal:hover,
.btn-tonal:focus-visible {
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  transform: translateY(-1px);
  background: rgba(255, 255, 255, 0.25);
  outline: none;
}

@media (max-width: 600px) {
  .hero-actions {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }
  .btn {
    width: 100%;
    max-width: 240px;
  }
}

.gallery-item {
  cursor: zoom-in;
  display: block;
}

.fallback-icon {
  font-size: 2.4rem;
  margin-bottom: 16px;
  opacity: 0.6;
}

.fallback-desc {
  font-size: 0.95rem;
  opacity: 0.85;
}

.code-block-container {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-top: 6px;
}

.code-block-container .code-block {
  margin-top: 0;
  flex: 1;
}

.btn-icon {
  background: transparent;
  border: none;
  color: var(--md-sys-color-primary);
  cursor: pointer;
  padding: 8px;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  transition: background-color 200ms var(--ease-out-quart);
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-icon:hover:not(:disabled) {
  background: var(--md-sys-color-surface-variant);
}

.btn-icon:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.google-cal-download {
  display: none;
}

.is-online .google-cal-download {
  display: flex;
}

.ios-gallery-controls,
.macos-gallery-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 12px;
}
#ios-gallery-counter,
#macos-gallery-counter {
  font-size: 0.9rem;
  color: var(--ink-muted);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}

.calendar-iframe {
  border: 0;
  overflow: hidden;
}

.gallery-window {
  overflow: hidden;
  border-radius: 8px;
  border: 1px solid var(--line);
  margin-top: 12px;
  background: transparent;
}

.ios-gallery-track,
.macos-gallery-track {
  display: flex;
  align-items: center;
  transition: transform 0.4s cubic-bezier(0.2, 0, 0, 1);
}

.gallery-item {
  flex: 0 0 100%;
  display: block;
}

.gallery-shot {
  width: 100%;
  display: block;
  border: none !important;
  margin: 0 !important;
  border-radius: 0 !important;
}
.custom-range-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.custom-range-selectors {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.5rem 0;
}
.select-wrapper {
  position: relative;
  flex: 1;
}
.select-wrapper select {
  width: 100%;
  padding: 0.75rem 2.5rem 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: var(--surface-color);
  color: var(--text-primary);
  appearance: none;
  font-family: inherit;
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition-speed) ease;
}
.select-wrapper select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px var(--primary-color-alpha);
}
.select-icon {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  pointer-events: none;
}
.range-separator {
  color: var(--text-secondary);
  font-weight: 500;
}