/* ===== Design Tokens ===== */
:root {
  color-scheme: dark;

  /* Color */
  --bg: #050914;
  --bg-deep: #02040b;
  --text: #f3f7ff;
  --muted: rgba(226, 237, 255, 0.68);
  --faint: rgba(226, 237, 255, 0.38);
  --ice: #82dfff;
  --ice-strong: #b9f1ff;
  --gold: #d8b86a;
  --panel: rgba(3, 8, 18, 0.62);
  --panel-border: rgba(165, 222, 234, 0.22);
  --focus-ring: rgba(130, 223, 255, 0.7);

  /* Canvas rendering (RGB tuples for JS canvas API) */
  --ice-rgb: 130, 223, 255;
  --ice-strong-rgb: 185, 241, 255;
  --gold-rgb: 216, 184, 106;
  --star-core-rgb: 235, 250, 255;
  --star-fill-rgb: 221, 238, 255;
  --dust-dim-rgb: 226, 244, 255;
  --path-ambient-rgb: 210, 232, 246;
  --path-start-rgb: 218, 244, 255;
  --label-rgb: 218, 244, 255;
  --star-shadow-rgb: 130, 223, 255;

  /* Typography */
  --body-font: Inter, "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC",
    "Noto Sans CJK SC", Arial, sans-serif;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 12px;
  --space-lg: 16px;
  --space-xl: 20px;
  --space-2xl: 24px;
  --space-3xl: 32px;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  /* Transition */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-fast: 180ms;
  --duration-normal: 260ms;
  --duration-slow: 520ms;
}

/* ===== Reset ===== */
* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-height: 100%;
  margin: 0;
  background: var(--bg-deep);
  color: var(--text);
  font-family: var(--body-font);
  overflow: hidden;
}

button,
a {
  font: inherit;
}

/* ===== Focus Ring (shared) ===== */
:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* ===== Main Stage ===== */
.star-road-app {
  position: relative;
  width: 100vw;
  height: 100svh;
  overflow: hidden;
  background:
    linear-gradient(
      90deg,
      rgba(2, 4, 11, 0.88) 0%,
      rgba(2, 4, 11, 0.46) 28%,
      rgba(2, 4, 11, 0.02) 58%,
      rgba(2, 4, 11, 0.16) 100%
    ),
    linear-gradient(
      180deg,
      rgba(2, 4, 11, 0.12) 0%,
      rgba(2, 4, 11, 0) 44%,
      rgba(2, 4, 11, 0.34) 100%
    ),
    linear-gradient(145deg, #07111f 0%, #050914 44%, #02040b 100%);
  isolation: isolate;
}

.star-road-app::before,
.star-road-app::after {
  position: absolute;
  inset: 0;
  content: "";
  pointer-events: none;
}

.star-road-app::before {
  opacity: 0.1;
  background-image:
    radial-gradient(
      circle,
      rgba(255, 255, 255, 0.54) 0 1px,
      transparent 1.4px
    ),
    radial-gradient(
      circle,
      rgba(216, 184, 106, 0.44) 0 1px,
      transparent 1.5px
    );
  background-position: 0 0, 42px 68px;
  background-size: 240px 280px, 360px 420px;
}

.star-road-app::after {
  background:
    radial-gradient(
      ellipse at 54% 46%,
      rgba(184, 231, 245, 0.11),
      transparent 34%
    ),
    radial-gradient(
      ellipse at center,
      transparent 0%,
      rgba(0, 0, 0, 0.32) 88%
    );
}

/* ===== Star Canvas ===== */
.star-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  display: block;
  touch-action: none;
  cursor: grab;
}

.star-canvas:active {
  cursor: grabbing;
}

/* ===== Hero Title ===== */
.hero-title {
  position: absolute;
  top: clamp(132px, 24vh, 210px);
  left: clamp(30px, 8vw, 126px);
  z-index: 3;
  max-width: min(430px, calc(100vw - 60px));
  pointer-events: none;
  transition:
    opacity var(--duration-slow) var(--ease-out),
    filter var(--duration-slow) var(--ease-out),
    transform var(--duration-slow) var(--ease-out);
}

.hero-title.is-stardust {
  opacity: 0;
  filter: blur(8px);
  transform: translateY(-10px);
}

.hero-kicker,
.hero-title h1,
.hero-subtitle {
  margin: 0;
  letter-spacing: 0;
}

.hero-kicker {
  margin-bottom: 18px;
  color: rgba(185, 241, 255, 0.66);
  font-size: 13px;
  line-height: 1;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

.hero-title h1 {
  font-size: clamp(56px, 7.4vw, 104px);
  font-weight: 500;
  line-height: 0.92;
  color: rgba(244, 250, 255, 0.96);
  text-shadow:
    0 0 30px rgba(2, 4, 11, 0.72),
    0 0 42px rgba(130, 223, 255, 0.18);
}

.hero-subtitle {
  margin-top: var(--space-xl);
  color: rgba(226, 237, 255, 0.78);
  font-size: clamp(18px, 2.1vw, 28px);
  font-weight: 300;
  line-height: 1.5;
  text-shadow: 0 0 22px rgba(2, 4, 11, 0.72);
}

/* ===== Compass Button ===== */
.compass-button {
  position: absolute;
  top: var(--space-xl);
  right: var(--space-xl);
  z-index: 6;
  display: grid;
  width: 42px;
  height: 42px;
  padding: 0;
  place-items: center;
  color: var(--ice-strong);
  background: rgba(4, 10, 22, 0.44);
  border: 1px solid rgba(165, 222, 234, 0.22);
  border-radius: 50%;
  box-shadow: 0 0 18px rgba(80, 179, 221, 0.1);
  cursor: pointer;
  backdrop-filter: blur(10px);
  transition:
    transform var(--duration-fast) var(--ease-out),
    box-shadow var(--duration-fast) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out);
}

.compass-button:hover {
  transform: scale(1.08);
  box-shadow: 0 0 24px rgba(80, 179, 221, 0.24);
  border-color: rgba(165, 222, 234, 0.44);
}

.compass-button:active {
  transform: scale(0.94);
}

/* Compass icon parts */
.compass-ring {
  position: absolute;
  width: 25px;
  height: 25px;
  border: 1px solid currentColor;
  border-radius: 50%;
  opacity: 0.82;
}

.compass-ring::before,
.compass-ring::after {
  position: absolute;
  content: "";
  background: currentColor;
}

.compass-ring::before {
  top: 50%;
  left: var(--space-xs);
  width: 15px;
  height: 1px;
}

.compass-ring::after {
  top: var(--space-xs);
  left: 50%;
  width: 1px;
  height: 15px;
}

.compass-core {
  width: 5px;
  height: 5px;
  background: currentColor;
  border-radius: 50%;
  box-shadow: 0 0 14px currentColor;
}

/* ===== Hidden Nav ===== */
.hidden-nav {
  position: absolute;
  top: 72px;
  right: var(--space-xl);
  z-index: 5;
  display: flex;
  gap: var(--space-sm);
  padding: 6px;
  pointer-events: none;
  opacity: 0;
  transform: translateY(-8px);
  transition:
    opacity var(--duration-fast) var(--ease-out),
    transform var(--duration-fast) var(--ease-out);
}

.hidden-nav.is-open {
  pointer-events: auto;
  opacity: 1;
  transform: translateY(0);
}

.hidden-nav a {
  min-width: 54px;
  padding: 9px var(--space-md);
  color: rgba(239, 249, 255, 0.76);
  text-align: center;
  text-decoration: none;
  background: rgba(5, 11, 24, 0.54);
  border: 1px solid rgba(165, 222, 234, 0.14);
  border-radius: var(--radius-md);
  backdrop-filter: blur(12px);
  transition:
    background var(--duration-fast) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out);
}

.hidden-nav a:hover {
  background: rgba(5, 11, 24, 0.7);
  border-color: rgba(165, 222, 234, 0.32);
  color: rgba(239, 249, 255, 0.95);
}

.hidden-nav a:active {
  background: rgba(5, 11, 24, 0.9);
}

/* ===== Detail Panel (Desktop) ===== */
.detail-panel {
  position: absolute;
  top: 100px;
  right: var(--space-xl);
  z-index: 4;
  width: min(352px, calc(100vw - 40px));
  padding: 22px 22px var(--space-xl);
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-md);
  box-shadow:
    0 22px 54px rgba(0, 0, 0, 0.32),
    0 0 24px rgba(89, 199, 255, 0.1);
  opacity: 0;
  transform: translateX(var(--space-lg));
  pointer-events: none;
  backdrop-filter: blur(18px);
  transition:
    opacity var(--duration-normal) var(--ease-out),
    transform var(--duration-normal) var(--ease-out);
}

.detail-panel.is-open {
  opacity: 1;
  transform: translateX(0);
  pointer-events: auto;
}

/* ===== Panel Close Button ===== */
.panel-close {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 28px;
  height: 28px;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition:
    color var(--duration-fast) var(--ease-out),
    background var(--duration-fast) var(--ease-out);
}

.panel-close:hover {
  color: var(--ice-strong);
  background: rgba(130, 223, 255, 0.08);
}

.panel-close:active {
  color: var(--ice);
  background: rgba(130, 223, 255, 0.14);
}

/* ===== Panel Content ===== */
.panel-eyebrow {
  margin: 0 0 10px;
  color: rgba(185, 241, 255, 0.72);
  font-size: var(--space-md);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.detail-panel h2,
.bottom-sheet h2 {
  margin: 0;
  font-size: 22px;
  line-height: 1.28;
  font-weight: 500;
}

.detail-panel p:last-child,
.bottom-sheet p:last-child {
  margin: 14px 0 0;
  color: rgba(226, 237, 255, 0.72);
  font-size: 14px;
  line-height: 1.75;
}

/* ===== Bottom Sheet (Mobile) ===== */
.bottom-sheet {
  position: absolute;
  right: var(--space-md);
  bottom: var(--space-md);
  left: var(--space-md);
  z-index: 4;
  padding: 18px 18px var(--space-xl);
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-md);
  box-shadow: 0 18px 56px rgba(0, 0, 0, 0.36);
  backdrop-filter: blur(18px);
  opacity: 0;
  transform: translateY(calc(100% + var(--space-md)));
  pointer-events: none;
  transition:
    opacity var(--duration-normal) var(--ease-out),
    transform var(--duration-normal) var(--ease-out);
}

.bottom-sheet.is-open {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

/* ===== Sheet Handle ===== */
.sheet-handle {
  display: block;
  width: 42px;
  height: var(--space-xs);
  margin: 0 auto 18px;
  background: rgba(220, 244, 255, 0.3);
  border: 0;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition:
    background var(--duration-fast) var(--ease-out),
    opacity var(--duration-fast) var(--ease-out);
}

.sheet-handle:hover {
  background: rgba(220, 244, 255, 0.5);
}

/* ===== Interaction Hint ===== */
.interaction-hint {
  position: absolute;
  right: 18px;
  bottom: 18px;
  z-index: 3;
  padding: 7px 10px;
  color: rgba(226, 237, 255, 0.44);
  font-size: var(--space-md);
  letter-spacing: 0.18em;
  background: rgba(5, 11, 24, 0.32);
  border: 1px solid rgba(142, 224, 255, 0.1);
  border-radius: var(--radius-md);
  transition: opacity var(--duration-fast) var(--ease-out);
}

.interaction-hint.is-hidden {
  opacity: 0;
}

/* ===== Noscript Fallback ===== */
.noscript-fallback {
  position: fixed;
  inset: 0;
  display: grid;
  padding: var(--space-3xl);
  place-content: center;
  color: var(--text);
  background: var(--bg);
}

/* ===== Mobile ===== */
@media (max-width: 760px) {
  html,
  body {
    overflow: auto;
  }

  .star-road-app {
    min-height: 100svh;
  }

  .hero-title {
    top: 132px;
    right: var(--space-xl);
    left: var(--space-xl);
    max-width: 92vw;
  }

  .compass-button {
    top: 14px;
    right: 14px;
  }

  .hidden-nav {
    top: 62px;
    right: 14px;
    flex-direction: column;
  }

  .detail-panel {
    display: none;
  }

  .interaction-hint {
    right: 14px;
    left: auto;
    bottom: 14px;
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
  }
}

/* ===== Personal Universe Map Skeleton ===== */
.universe-app {
  position: relative;
  width: 100vw;
  height: 100svh;
  overflow: hidden;
  overscroll-behavior: none;
  background: #02040b;
  isolation: isolate;
}

.universe-canvas {
  position: absolute;
  inset: 0;
  z-index: 1;
  display: block;
  width: 100%;
  height: 100%;
  cursor: crosshair;
  overscroll-behavior: none;
  touch-action: none;
}

.universe-app[data-render-mode="fallback"] .universe-canvas,
.universe-app[data-render-mode="fallback"] .intro-screen {
  display: none;
}

.universe-fallback {
  position: absolute;
  inset: 0;
  z-index: 4;
  display: grid;
  place-items: center;
  overflow: hidden;
  color: rgba(227, 240, 241, 0.92);
  background:
    radial-gradient(ellipse at 64% 42%, rgba(30, 93, 108, 0.48), transparent 31%),
    radial-gradient(ellipse at 31% 62%, rgba(9, 34, 49, 0.92), transparent 42%),
    #010407;
}

.universe-fallback[hidden] {
  display: none;
}

.universe-fallback__ink {
  position: absolute;
  width: min(82vw, 900px);
  aspect-ratio: 1.8;
  opacity: 0.84;
  filter: blur(1px);
  background:
    radial-gradient(ellipse at 32% 52%, rgba(87, 148, 160, 0.54), transparent 11%),
    radial-gradient(ellipse at 58% 38%, rgba(38, 105, 122, 0.66), transparent 23%),
    radial-gradient(ellipse at 74% 62%, rgba(101, 148, 156, 0.26), transparent 14%);
  transform: rotate(-9deg) scale(1.36);
}

.universe-fallback__content {
  position: relative;
  display: grid;
  gap: 10px;
  max-width: min(360px, calc(100vw - 48px));
  text-align: center;
  text-shadow: 0 4px 24px rgba(0, 0, 0, 0.8);
}

.universe-fallback__content p {
  margin: 0;
  font-size: clamp(23px, 4vw, 38px);
  font-weight: 400;
}

.universe-fallback__content span {
  color: rgba(194, 215, 219, 0.68);
  font-size: 14px;
}

.intro-screen {
  position: fixed;
  inset: 0;
  z-index: 5;
  display: grid;
  place-items: center;
  padding: 32px;
  background: #000;
  opacity: 1;
  pointer-events: auto;
  transition:
    opacity 960ms cubic-bezier(0.16, 1, 0.3, 1),
    filter 960ms cubic-bezier(0.16, 1, 0.3, 1);
}

.intro-screen::after {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  content: "";
  background: rgba(244, 252, 255, 0);
  box-shadow:
    0 0 0 rgba(185, 241, 255, 0),
    0 0 0 rgba(130, 223, 255, 0);
  transform: translate(-50%, -50%) scale(0.2);
  transition:
    background 520ms cubic-bezier(0.16, 1, 0.3, 1),
    box-shadow 720ms cubic-bezier(0.16, 1, 0.3, 1),
    transform 720ms cubic-bezier(0.16, 1, 0.3, 1);
}

.intro-message {
  width: min(520px, calc(100vw - 48px));
  color: rgba(244, 250, 255, 0.92);
  font-size: clamp(24px, 4.8vw, 52px);
  font-weight: 300;
  line-height: 1.45;
  letter-spacing: 0;
  opacity: 0;
  filter: blur(8px);
  transform: scale(1.04);
  transition:
    opacity 760ms cubic-bezier(0.16, 1, 0.3, 1),
    filter 760ms cubic-bezier(0.16, 1, 0.3, 1),
    transform 920ms cubic-bezier(0.16, 1, 0.3, 1);
}

.intro-message p {
  margin: 0;
}

.intro-signature {
  margin-top: 14px;
  color: rgba(226, 237, 255, 0.72);
  font-size: 0.58em;
  text-align: right;
}

.intro-screen[data-phase="message"] .intro-message {
  opacity: 1;
  filter: blur(0);
  transform: scale(1);
}

.intro-screen[data-phase="collapse"] .intro-message {
  opacity: 0.18;
  filter: blur(12px);
  transform: scale(0.02);
}

.intro-screen[data-phase="collapse"]::after,
.intro-screen[data-phase="reveal"]::after {
  background: rgba(244, 252, 255, 1);
  box-shadow:
    0 0 28px rgba(185, 241, 255, 0.88),
    0 0 92px rgba(130, 223, 255, 0.68);
  transform: translate(-50%, -50%) scale(1);
}

.intro-screen[data-phase="reveal"],
.intro-screen[data-phase="done"] {
  opacity: 0;
  filter: blur(10px);
  pointer-events: none;
}

.reading-overlay {
  position: fixed;
  inset: 0;
  z-index: 6;
  display: grid;
  place-items: center;
  padding: clamp(18px, 4vw, 48px);
  background:
    radial-gradient(circle at 50% 42%, rgba(12, 42, 62, 0.34), rgba(2, 4, 11, 0.84) 58%),
    rgba(0, 0, 0, 0.42);
  opacity: 0;
  pointer-events: none;
  backdrop-filter: blur(8px);
  transition: opacity 260ms cubic-bezier(0.16, 1, 0.3, 1);
}

.reading-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

.reading-content {
  width: min(760px, 100%);
  max-height: min(78svh, 780px);
  overflow: auto;
  padding: clamp(26px, 5vw, 56px);
  color: rgba(244, 250, 255, 0.94);
  background:
    linear-gradient(180deg, rgba(8, 20, 32, 0.64), rgba(2, 4, 11, 0.7)),
    rgba(2, 4, 11, 0.58);
  border: 1px solid rgba(185, 241, 255, 0.14);
  border-radius: 8px;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.46);
}

.reading-header h1 {
  margin: 0;
  color: rgba(244, 250, 255, 0.96);
  font-size: clamp(30px, 5vw, 54px);
  font-weight: 500;
  line-height: 1.1;
}

.reading-date {
  margin: 0 0 12px;
  color: rgba(185, 241, 255, 0.58);
  font-size: 13px;
}

.reading-summary {
  margin: 18px 0 0;
  color: rgba(226, 237, 255, 0.72);
  font-size: 17px;
  line-height: 1.8;
}

.reading-body {
  margin-top: 34px;
  color: rgba(226, 237, 255, 0.82);
  font-size: 16px;
  line-height: 1.9;
}

.reading-body h2,
.reading-body h3 {
  margin: 32px 0 12px;
  color: rgba(244, 250, 255, 0.94);
  font-weight: 500;
}

.reading-body p {
  margin: 0 0 18px;
}

.reading-close {
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 7;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  color: rgba(226, 237, 255, 0.72);
  background: rgba(2, 4, 11, 0.42);
  border: 1px solid rgba(185, 241, 255, 0.16);
  border-radius: 50%;
  cursor: pointer;
}

.reading-close:hover {
  color: rgba(244, 250, 255, 0.96);
  border-color: rgba(185, 241, 255, 0.34);
}

.noscript-fallback {
  position: fixed;
  inset: 0;
  display: grid;
  place-content: center;
  padding: 32px;
  color: #f3f7ff;
  background: #02040b;
  text-align: center;
}

@media (max-width: 760px) {
  html,
  body {
    overflow: hidden;
  }

  .intro-message {
    width: min(340px, calc(100vw - 42px));
  }

  .reading-overlay {
    align-items: end;
    padding: 18px;
  }

  .reading-content {
    max-height: 76svh;
    padding: 26px 22px;
  }

  .reading-close {
    top: 14px;
    right: 14px;
    width: 40px;
    height: 40px;
  }
}