/* ══════════════════════════════════════════════════════════════
   Portal — Berserk · Iron & Blood · Single Viewport
   No scroll. All interaction within 100vh.
   ══════════════════════════════════════════════════════════════ */

/* ── Custom Properties ─────────────────────────────────────── */
:root {
  /* Palette */
  --bg-abyss:     oklch(0.03 0.003 30);
  --bg-deep:      oklch(0.06 0.004 28);
  --surface:      oklch(0.10 0.006 25);
  --surface-hover: oklch(0.14 0.008 22);
  --border:       oklch(0.22 0.010 20);
  --border-soft:  oklch(0.28 0.010 20 / 0.30);
  --border-glass: oklch(0.65 0.03 240 / 0.15);

  --ink:          oklch(0.90 0.012 85);
  --ink-soft:     oklch(0.78 0.010 82);
  --ink-muted:    oklch(0.58 0.006 80);
  --ink-dim:      oklch(0.38 0.005 78);

  --blood:        oklch(0.50 0.22 22);
  --blood-bright: oklch(0.56 0.21 20);
  --blood-glow:   oklch(0.50 0.22 22 / 0.25);
  --blood-dim:    oklch(0.35 0.15 22 / 0.50);

  --iron:         oklch(0.55 0.03 240);
  --iron-bright:  oklch(0.68 0.04 235);
  --iron-glow:    oklch(0.55 0.03 240 / 0.18);
  --iron-glass:   oklch(0.55 0.03 240 / 0.08);

  /* Typography */
  --font-display: 'Georgia', 'Times New Roman', 'Noto Serif SC', serif;
  --font-body:    'PingFang SC', 'Microsoft YaHei', 'Noto Serif SC', 'Hiragino Sans GB', 'STSong', serif;
  --font-mono:    'Consolas', 'Courier New', 'Monaco', monospace;

  /* Sizing */
  --sidebar-w: 370px;
  --topbar-h: 56px;

  /* Motion */
  --ease-out:  cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --dur-fast:  180ms;
  --dur-normal: 400ms;
  --dur-slow:   700ms;
  --dur-glacial: 1200ms;

  /* Z-index layers */
  --z-bg:     0;
  --z-particles: 1;
  --z-content: 10;
  --z-sidebar: 20;
  --z-topbar:  30;
  --z-player:  40;
}

/* ── Reset ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow: hidden;
  height: 100%;
}
body {
  font-family: var(--font-body);
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg-abyss);
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  position: relative;
}
::selection {
  background: oklch(0.50 0.22 22 / 0.35);
  color: var(--ink);
}
a {
  color: var(--iron-bright);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}
a:hover { color: var(--ink); }
:focus-visible {
  outline: 2px solid var(--iron);
  outline-offset: 2px;
}
img { display: block; max-width: 100%; }

/* ══════════════════════════════════════════════════════════════
   Background Layer
   ══════════════════════════════════════════════════════════════ */
.bg-layer {
  position: fixed;
  inset: 0;
  z-index: var(--z-bg);
  overflow: hidden;
}

/* The Berserk image — scaled to cover, slightly zoomed and panned */
.bg-image {
  position: absolute;
  inset: -5%;
  width: 110%;
  height: 110%;
  object-fit: cover;
  object-position: center 30%;
  filter: saturate(0.6) contrast(1.15) brightness(0.55);
  animation: bg-drift 30s ease-in-out infinite alternate;
}

@keyframes bg-drift {
  0%   { transform: scale(1) translate(0, 0); }
  100% { transform: scale(1.06) translate(-1.5%, -1%); }
}

/* Heavy vignette — dark edges, focused center */
.bg-vignette {
  position: absolute;
  inset: 0;
  background:
    /* Radial vignette */
    radial-gradient(
      ellipse 75% 70% at 45% 48%,
      transparent 30%,
      oklch(0.02 0.002 30 / 0.45) 65%,
      oklch(0.01 0.001 30 / 0.85) 100%
    ),
    /* Bottom-heavy shadow */
    linear-gradient(
      to top,
      oklch(0.01 0.001 30 / 0.7) 0%,
      transparent 50%
    ),
    /* Left-edge shadow for depth */
    linear-gradient(
      to right,
      oklch(0.01 0.001 30 / 0.4) 0%,
      transparent 25%
    );
  pointer-events: none;
}

/* Subtle scanline / CRT grain overlay */
.bg-scanline {
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    oklch(0 0 0 / 0.03) 2px,
    oklch(0 0 0 / 0.03) 4px
  );
  pointer-events: none;
  opacity: 0.5;
}

/* Three.js canvas — sits between bg image and content */
#bg-canvas {
  position: fixed;
  inset: 0;
  z-index: var(--z-particles);
  pointer-events: none;
  mix-blend-mode: screen;
}

/* ══════════════════════════════════════════════════════════════
   App Shell — all UI in one viewport
   ══════════════════════════════════════════════════════════════ */
.app-shell {
  position: relative;
  z-index: var(--z-content);
  width: 100%;
  height: 100vh;
  height: 100dvh;
  display: grid;
  grid-template-rows: var(--topbar-h) 1fr auto;
  grid-template-columns: 1fr;
  pointer-events: none;  /* let clicks pass through empty areas to sidebar trigger */
}

.app-shell > * {
  pointer-events: auto;
}

/* ══════════════════════════════════════════════════════════════
   Top Bar — yoiwerr brand
   ══════════════════════════════════════════════════════════════ */
.top-bar {
  display: flex;
  align-items: center;
  padding: 0 2rem;
  z-index: var(--z-topbar);
}

.brand {
  position: relative;
  display: inline-flex;
  align-items: center;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink);
  text-shadow:
    0 0 20px oklch(0.55 0.03 240 / 0.25),
    0 0 60px oklch(0.55 0.03 240 / 0.10),
    0 1px 0 oklch(0.7 0.04 235 / 0.15);
  transition: text-shadow var(--dur-slow) var(--ease-out);
  user-select: none;
}

.brand:hover {
  text-shadow:
    0 0 28px oklch(0.55 0.03 240 / 0.40),
    0 0 80px oklch(0.55 0.03 240 / 0.18),
    0 1px 0 oklch(0.7 0.04 235 / 0.25);
}

/* Subtle metallic glint that sweeps across */
.brand-glint {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    105deg,
    transparent 40%,
    oklch(1 0 0 / 0.06) 45%,
    oklch(1 0 0 / 0.12) 50%,
    oklch(1 0 0 / 0.06) 55%,
    transparent 60%
  );
  background-size: 200% 100%;
  animation: glint-sweep 4s ease-in-out infinite;
  pointer-events: none;
}

@keyframes glint-sweep {
  0%, 100% { background-position: 200% 0; }
  50%      { background-position: -200% 0; }
}

/* ══════════════════════════════════════════════════════════════
   Right Sidebar — Expandable
   ══════════════════════════════════════════════════════════════ */
.sidebar {
  position: fixed;
  top: 0;
  right: 0;
  height: 100vh;
  height: 100dvh;
  z-index: var(--z-sidebar);
  display: flex;
  /* pointer-events handled by children — trigger is always clickable,
     panel only receives events when expanded (width > 0) */
}

/* ── Trigger button — always visible ────────────────────────── */
.sidebar-trigger {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  min-width: 44px;
  height: 100%;
  cursor: pointer;
  pointer-events: auto;
  z-index: 2;
  transition: background var(--dur-normal) var(--ease-out);
}

.trigger-bars {
  font-size: 1.3rem;
  color: var(--ink-muted);
  transition: all var(--dur-normal) var(--ease-out);
  text-shadow: 0 0 12px oklch(0.55 0.03 240 / 0.18);
  user-select: none;
  background: oklch(0.08 0.005 30 / 0.6);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  border: 1px solid var(--border-soft);
}

/* ── Panel — slides in from right ───────────────────────────── */
.sidebar-panel {
  width: 0;
  overflow-x: hidden;
  overflow-y: auto;
  height: 100%;
  background: oklch(0.06 0.004 28 / 0.75);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-left: 1px solid transparent;
  transition:
    width 0.5s var(--ease-spring),
    border-color 0.4s var(--ease-out);
  pointer-events: auto;
}

.sidebar-panel::-webkit-scrollbar {
  width: 3px;
}
.sidebar-panel::-webkit-scrollbar-thumb {
  background: oklch(0.55 0.03 240 / 0.2);
  border-radius: 3px;
}

/* Expanded state — triggered by hovering the sidebar area */
.sidebar:hover .sidebar-panel,
.sidebar.expanded .sidebar-panel {
  width: var(--sidebar-w);
  border-left-color: oklch(0.55 0.03 240 / 0.15);
}

.sidebar:hover .trigger-bars,
.sidebar.expanded .trigger-bars {
  color: var(--iron-bright);
  text-shadow: 0 0 20px oklch(0.55 0.03 240 / 0.35);
  background: oklch(0.12 0.008 28 / 0.7);
  border-color: oklch(0.55 0.03 240 / 0.3);
}

/* ── Panel Inner ────────────────────────────────────────────── */
.panel-inner {
  width: var(--sidebar-w);
  padding: 1.5rem 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  opacity: 0;
  transition: opacity 0.3s var(--ease-out) 0.15s;
}

.sidebar:hover .panel-inner,
.sidebar.expanded .panel-inner {
  opacity: 1;
}

.panel-title {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 0.25rem;
}

/* ── Glass Card (ChatLab) ───────────────────────────────────── */
.glass-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 1.5rem 1.25rem;
  border-radius: 14px;
  background:
    radial-gradient(
      circle at 50% 30%,
      oklch(0.68 0.04 235 / 0.08) 0%,
      oklch(0.12 0.008 30 / 0.30) 60%,
      oklch(0.08 0.006 25 / 0.50) 100%
    );
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid oklch(0.55 0.03 240 / 0.14);
  box-shadow:
    inset 0 1px 0 oklch(1 0 0 / 0.06),
    0 4px 32px oklch(0 0 0 / 0.35),
    0 0 0 1px oklch(0.55 0.03 240 / 0.04);
  transition:
    transform 0.4s var(--ease-out),
    box-shadow 0.5s var(--ease-out),
    border-color 0.3s var(--ease-out);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}

.glass-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(
    circle at 60% 20%,
    oklch(0.68 0.04 235 / 0.12) 0%,
    transparent 65%
  );
  pointer-events: none;
  transition: opacity 0.4s var(--ease-out);
}

.glass-card:hover {
  transform: translateY(-3px);
  border-color: oklch(0.68 0.04 235 / 0.28);
  box-shadow:
    inset 0 1px 0 oklch(1 0 0 / 0.10),
    0 8px 40px oklch(0 0 0 / 0.50),
    0 0 0 1px oklch(0.55 0.03 240 / 0.10),
    0 0 60px oklch(0.55 0.03 240 / 0.06);
}

.glass-card:active { transform: translateY(-1px); }

.glass-card-icon {
  font-size: 1.6rem;
  margin-bottom: 0.5rem;
  display: block;
}

.glass-card-badge {
  display: inline-block;
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 0.55rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--iron-bright);
  background: oklch(0.55 0.03 240 / 0.15);
  padding: 0.15rem 0.55rem;
  border-radius: 99px;
  margin-bottom: 0.65rem;
}

.glass-card-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 0.5rem;
}

.glass-card-desc {
  font-size: 0.7rem;
  color: var(--ink-muted);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 0.75rem;
}

.glass-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.85rem;
}

.glass-card-tags span {
  font-size: 0.58rem;
  font-family: var(--font-mono);
  color: var(--ink-dim);
  border: 1px solid oklch(0.28 0.010 20 / 0.30);
  padding: 0.18rem 0.5rem;
  border-radius: 99px;
}

.glass-card-cta {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 500;
  color: var(--iron-bright);
  align-self: flex-start;
  transition: color var(--dur-fast);
}

.glass-card:hover .glass-card-cta {
  color: var(--ink);
}

/* Placeholder card */
.placeholder-card {
  align-items: center;
  justify-content: center;
  min-height: 120px;
  border-style: dashed;
  border-color: oklch(0.25 0.010 20 / 0.25);
  background: transparent;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}
.placeholder-card:hover {
  transform: none;
  box-shadow: none;
  border-color: oklch(0.35 0.010 22 / 0.35);
}
.placeholder-card::before { display: none; }
.placeholder-mark {
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--ink-dim);
  opacity: 0.3;
  margin-bottom: 0.4rem;
}
.placeholder-card p {
  font-size: 0.65rem;
  color: var(--ink-dim);
}

/* ══════════════════════════════════════════════════════════════
   BGM Player — Bottom Left
   ══════════════════════════════════════════════════════════════ */
.bgm-player {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: var(--z-player);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.5rem 0.75rem;
  background: oklch(0.06 0.004 28 / 0.55);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid oklch(0.28 0.010 20 / 0.25);
  border-radius: 12px;
  transition: border-color var(--dur-normal), box-shadow var(--dur-normal);
}

.bgm-player:hover {
  border-color: oklch(0.55 0.03 240 / 0.25);
  box-shadow: 0 0 24px oklch(0.55 0.03 240 / 0.08);
}

/* Play/Pause button */
.bgm-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1px solid oklch(0.55 0.03 240 / 0.2);
  border-radius: 50%;
  background: oklch(0.10 0.006 25 / 0.6);
  color: var(--ink-soft);
  cursor: pointer;
  font-size: 0.65rem;
  flex-shrink: 0;
  transition: all var(--dur-fast) var(--ease-out);
}

.bgm-toggle:hover {
  border-color: oklch(0.68 0.04 235 / 0.4);
  color: var(--ink);
  box-shadow: 0 0 14px oklch(0.55 0.03 240 / 0.15);
}

/* Show/hide play vs pause icon */
.bgm-toggle .bgm-icon-pause { display: none; }
.bgm-toggle.playing .bgm-icon-play { display: none; }
.bgm-toggle.playing .bgm-icon-pause { display: inline; }

/* Volume slider */
.bgm-volume-wrap {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.bgm-volume {
  -webkit-appearance: none;
  appearance: none;
  width: 64px;
  height: 3px;
  border-radius: 3px;
  background: oklch(0.28 0.010 20 / 0.40);
  outline: none;
  cursor: pointer;
}

.bgm-volume::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--iron-bright);
  border: none;
  box-shadow: 0 0 8px oklch(0.55 0.03 240 / 0.3);
  cursor: pointer;
  transition: transform var(--dur-fast), box-shadow var(--dur-fast);
}

.bgm-volume::-webkit-slider-thumb:hover {
  transform: scale(1.3);
  box-shadow: 0 0 14px oklch(0.55 0.03 240 / 0.45);
}

.bgm-volume::-moz-range-thumb {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--iron-bright);
  border: none;
  box-shadow: 0 0 8px oklch(0.55 0.03 240 / 0.3);
  cursor: pointer;
}

.bgm-label {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-dim);
  user-select: none;
}

.bgm-track {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  color: var(--ink-soft);
  max-width: 140px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  opacity: 0;
  transition: opacity 0.3s var(--ease-out);
}

.bgm-track.show {
  opacity: 1;
}

/* ══════════════════════════════════════════════════════════════
   Animation Keyframes
   ══════════════════════════════════════════════════════════════ */

/* Floating tagline cursor blink */
@keyframes cursor-blink {
  0%, 100% { opacity: 0.3; }
  50%      { opacity: 0.7; }
}

/* ══════════════════════════════════════════════════════════════
   Entrance states (controlled by GSAP)
   ══════════════════════════════════════════════════════════════ */
.brand.pre-entrance {
  opacity: 0;
  transform: translateY(-12px);
}

/* ══════════════════════════════════════════════════════════════
   Responsive
   ══════════════════════════════════════════════════════════════ */
@media (max-width: 900px) {
  :root {
    --sidebar-w: 300px;
  }

  .sidebar-panel {
    position: fixed;
    right: 0;
    top: 0;
    bottom: 0;
    width: 0;
  }

  .sidebar:hover .sidebar-panel,
  .sidebar.expanded .sidebar-panel {
    width: var(--sidebar-w);
  }

  .glass-card {
    padding: 1rem;
  }

  .bgm-player {
    bottom: 1rem;
    right: 0.75rem;
    padding: 0.4rem 0.6rem;
  }

  .bgm-volume {
    width: 48px;
  }
}

@media (max-width: 600px) {
  :root {
    --sidebar-w: 280px;
  }

  .top-bar {
    padding: 0 1rem;
  }

  .brand {
    font-size: 1rem;
  }

  .bgm-player {
    bottom: 0.75rem;
    left: 0.5rem;
    gap: 0.4rem;
    padding: 0.35rem 0.5rem;
    border-radius: 10px;
  }
}

/* ── Reduced Motion ─────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  #bg-canvas { display: none; }
  .bg-image { animation: none; }
  .brand-glint { display: none; }
}