/* 落英溪 — 創意寫作小站 */

:root {
  color-scheme: light;
  --bg: oklch(0.972 0.018 165);
  --bg-soft: oklch(0.942 0.028 165);
  --surface: oklch(0.992 0.012 155 / 0.94);
  --surface-muted: oklch(0.965 0.022 165 / 0.88);
  --line: oklch(0.82 0.04 170 / 0.55);
  --text: oklch(0.32 0.05 170);
  --text-soft: oklch(0.46 0.04 172);
  --accent: oklch(0.52 0.12 165);
  --accent-soft: oklch(0.78 0.08 165);
  --water: oklch(0.58 0.1 215);
  --blossom: oklch(0.72 0.14 355);
  --shadow: 0 22px 50px oklch(0.45 0.06 180 / 0.1);
  --radius-lg: 22px;
  --radius-md: 14px;
  --font-sans: "Noto Sans TC", system-ui, sans-serif;
  --font-serif: "Noto Serif TC", Georgia, serif;
  --rail-width: min(384px, 92vw);
  --top-h: 56px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.65;
  color: var(--text);
  background:
    radial-gradient(ellipse 90% 50% at 12% -10%, oklch(0.92 0.06 350 / 0.35), transparent 55%),
    radial-gradient(ellipse 70% 45% at 88% 8%, oklch(0.88 0.08 215 / 0.22), transparent 50%),
    linear-gradient(168deg, var(--bg) 0%, var(--bg-soft) 55%, oklch(0.956 0.024 155) 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.45;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120' viewBox='0 0 120 120'%3E%3Ccircle cx='20' cy='24' r='1.6' fill='%2388a89a' opacity='0.25'/%3E%3Ccircle cx='90' cy='70' r='1.4' fill='%23c97b9e' opacity='0.2'/%3E%3Ccircle cx='60' cy='96' r='1.2' fill='%2390b8c4' opacity='0.22'/%3E%3C/svg%3E");
  z-index: 0;
}

.app-root {
  position: relative;
  z-index: 1;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.top-bar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  min-height: var(--top-h);
  padding: 10px 16px 10px 20px;
  background: oklch(0.988 0.015 155 / 0.82);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-right: auto;
}

.brand h1 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.25rem;
  letter-spacing: 0.06em;
  color: oklch(0.38 0.08 165);
}

.brand span {
  font-size: 0.72rem;
  color: var(--text-soft);
  letter-spacing: 0.02em;
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.status-pill {
  font-size: 0.75rem;
  color: var(--text-soft);
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--surface-muted);
  border: 1px solid var(--line);
}

.status-pill[hidden] {
  display: none;
}

.link-back {
  font-size: 0.875rem;
  color: var(--accent);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid transparent;
}

.link-back:hover {
  border-color: var(--line);
  background: var(--surface);
}

.layout {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr var(--rail-width);
  gap: 0;
  align-items: stretch;
  max-width: 1320px;
  margin: 0 auto;
  width: 100%;
}

.canvas-col {
  padding: 20px 20px 96px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-width: 0;
}

.seed-panel {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.seed-input {
  flex: 1 1 220px;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: var(--surface);
  font-size: 0.95rem;
  font-family: inherit;
  color: inherit;
  box-shadow: inset 0 1px 0 oklch(1 0 0 / 0.5);
}

.seed-input:focus {
  outline: 2px solid var(--accent-soft);
  outline-offset: 2px;
}

.tag-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  border: none;
  margin: 0;
  padding: 0;
}

.tag-chips legend {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.tag-chips label {
  cursor: pointer;
}

.tag-chips input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.tag-chips span {
  display: inline-block;
  padding: 7px 12px;
  border-radius: 999px;
  font-size: 0.82rem;
  border: 1px solid var(--line);
  background: oklch(0.99 0.01 165 / 0.6);
  color: var(--text-soft);
  transition: background 0.15s ease, border-color 0.15s ease;
}

.tag-chips input:checked + span {
  background: var(--accent-soft);
  border-color: oklch(0.55 0.08 165 / 0.45);
  color: var(--text);
}

.canvas-card {
  position: relative;
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 320px;
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, oklch(0.997 0.008 90 / 0.97), oklch(0.99 0.012 155 / 0.98)),
    var(--surface);
  border: 1px solid oklch(0.86 0.03 160 / 0.65);
  box-shadow: var(--shadow), inset 0 1px 0 oklch(1 0 0 / 0.85);
  overflow: hidden;
}

.canvas-card::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -20%;
  width: 52%;
  height: 72%;
  background: radial-gradient(circle, oklch(0.9 0.06 350 / 0.12), transparent 68%);
  pointer-events: none;
}

.opening-slot {
  padding: 16px 20px 0;
  flex-shrink: 0;
}

.opening-card {
  border-radius: var(--radius-md);
  padding: 14px 16px;
  background: linear-gradient(120deg, oklch(0.97 0.04 200 / 0.5), oklch(0.98 0.03 355 / 0.35));
  border: 1px dashed oklch(0.72 0.06 175 / 0.45);
  font-size: 0.92rem;
  color: var(--text-soft);
}

.opening-card[hidden] {
  display: none;
}

.opening-card p {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-size: 0.98rem;
  color: var(--text);
  line-height: 1.7;
}

.opening-actions,
.row-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.manuscript-wrap {
  flex: 1;
  padding: 12px 16px 18px;
  display: flex;
  min-height: 240px;
}

#manuscript {
  flex: 1;
  width: 100%;
  resize: vertical;
  min-height: 220px;
  border: none;
  background: transparent;
  font-family: var(--font-sans);
  font-size: 1.05rem;
  line-height: 1.85;
  color: inherit;
}

#manuscript:focus {
  outline: none;
}

#manuscript::placeholder {
  color: oklch(0.62 0.03 172);
}

.puzzle-strip {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 25;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 10px 16px 14px;
  padding-bottom: calc(14px + env(safe-area-inset-bottom));
  background: linear-gradient(
    to top,
    oklch(0.98 0.018 155 / 0.94) 78%,
    transparent
  );
  backdrop-filter: blur(10px);
  pointer-events: none;
}

.puzzle-strip .inner {
  pointer-events: auto;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
  max-width: 520px;
}

.piece-tip {
  pointer-events: auto;
  margin: 0;
  font-size: 0.72rem;
  color: oklch(0.52 0.04 175);
}

.piece-btn {
  position: relative;
  border: none;
  cursor: pointer;
  padding: 10px 16px 10px 18px;
  font-family: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--text-soft);
  background: var(--surface);
  border-radius: 4px;
  clip-path: polygon(
    0 0,
    calc(100% - 10px) 0,
    100% 10px,
    100% 100%,
    10px 100%,
    0 calc(100% - 10px)
  );
  border: 1px solid var(--line);
  box-shadow: 0 4px 12px oklch(0.4 0.04 180 / 0.07);
  transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease;
}

.piece-btn:hover {
  transform: translateY(-2px);
  color: var(--text);
}

.piece-btn[aria-pressed="true"] {
  background: linear-gradient(145deg, var(--accent-soft), oklch(0.93 0.05 200 / 0.9));
  color: oklch(0.34 0.08 165);
  border-color: oklch(0.62 0.1 165 / 0.5);
}

.piece-btn:focus-visible {
  outline: 2px solid var(--water);
  outline-offset: 2px;
}

.rail-toggle {
  display: none;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--surface);
  font-family: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
  cursor: pointer;
  box-shadow: 0 4px 14px oklch(0.45 0.05 175 / 0.12);
}

.rail-overlay {
  display: none;
}

.rail {
  border-left: 1px solid var(--line);
  background: oklch(0.982 0.02 170 / 0.92);
  backdrop-filter: blur(14px);
  display: flex;
  flex-direction: column;
  min-height: calc(100dvh - var(--top-h));
}

.rail-header {
  padding: 16px 16px 8px;
  border-bottom: 1px solid oklch(0.9 0.02 172 / 0.5);
}

.rail-tabs {
  display: flex;
  gap: 6px;
}

.rail-tabs button {
  flex: 1;
  cursor: pointer;
  padding: 10px 8px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  font-family: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-soft);
  background: transparent;
  transition: background 0.15s ease, color 0.15s ease;
}

.rail-tabs button:hover {
  background: var(--surface-muted);
  color: var(--text);
}

.rail-tabs button[aria-selected="true"] {
  background: var(--surface);
  border-color: var(--line);
  color: var(--accent);
  box-shadow: 0 2px 8px oklch(0.5 0.04 180 / 0.06);
}

.rail-panel {
  flex: 1;
  overflow: auto;
  padding: 16px;
}

.rail-pane {
  display: none;
  flex-direction: column;
  gap: 14px;
}

.rail-pane.is-active {
  display: flex;
}

.rail-pane h2 {
  margin: 0;
  font-size: 0.95rem;
  font-weight: 600;
  color: oklch(0.36 0.07 172);
}

.rail-pane .hint {
  margin: -6px 0 0;
  font-size: 0.82rem;
  color: var(--text-soft);
  line-height: 1.5;
}

.btn {
  cursor: pointer;
  padding: 10px 18px;
  border-radius: 999px;
  border: none;
  font-family: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  background: linear-gradient(135deg, oklch(0.5 0.11 168), oklch(0.42 0.1 215));
  color: oklch(0.99 0.01 165);
  box-shadow: 0 8px 20px oklch(0.45 0.1 175 / 0.22);
}

.btn:hover {
  filter: brightness(1.06);
}

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

.btn-secondary {
  background: var(--surface);
  color: var(--accent);
  border: 1px solid oklch(0.7 0.06 170 / 0.55);
  box-shadow: none;
}

.btn-ghost {
  background: transparent;
  color: var(--water);
  border: none;
  box-shadow: none;
  padding: 8px 12px;
  font-weight: 500;
}

.secondary-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.branch-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.branch-card {
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: var(--surface);
  overflow: hidden;
}

.branch-card summary {
  cursor: pointer;
  padding: 12px 14px;
  font-weight: 600;
  font-size: 0.88rem;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.branch-card summary::-webkit-details-marker {
  display: none;
}

.branch-card summary::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--blossom);
  opacity: 0.7;
}

.branch-card .sub {
  margin: 0;
  padding: 0 14px 8px;
  font-size: 0.82rem;
  color: var(--text-soft);
}

.branch-card .bullets {
  margin: 0;
  padding: 0 14px 12px 28px;
  font-size: 0.85rem;
  color: var(--text);
}

.branch-card .bullets li {
  margin-bottom: 6px;
}

.branch-card .insert-row {
  padding: 0 12px 12px;
}

.stuck-gate {
  font-size: 0.8rem;
  color: var(--text-soft);
  padding: 10px 12px;
  border-radius: var(--radius-md);
  background: oklch(0.96 0.02 175 / 0.8);
  border: 1px dashed var(--line);
}

.stuck-gate .btn {
  margin-top: 8px;
}

.img-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.img-tile {
  position: relative;
  border: none;
  padding: 0;
  border-radius: 12px;
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 4/3;
  box-shadow: 0 4px 14px oklch(0.4 0.04 180 / 0.12);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.img-tile:hover {
  transform: scale(1.02);
  box-shadow: 0 8px 22px oklch(0.4 0.06 180 / 0.18);
}

.img-tile img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.img-tile[aria-pressed="true"] {
  outline: 3px solid var(--water);
  outline-offset: 2px;
}

.img-preview {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--line);
}

.img-preview img {
  width: 100%;
  display: block;
  max-height: 200px;
  object-fit: cover;
}

.img-question {
  margin: 0;
  padding: 12px;
  font-size: 0.88rem;
  background: var(--surface-muted);
}

.watermark-wrap {
  position: relative;
}

.watermark-preview {
  position: absolute;
  bottom: 12px;
  right: 12px;
  width: min(120px, 32%);
  border-radius: 10px;
  overflow: hidden;
  opacity: 0.38;
  pointer-events: none;
  box-shadow: 0 6px 20px oklch(0.3 0.04 200 / 0.2);
  border: 1px solid oklch(1 0 0 / 0.4);
}

.watermark-preview img {
  width: 100%;
  display: block;
}

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

  .rail-toggle {
    display: inline-flex;
  }

  .rail {
    position: fixed;
    top: var(--top-h);
    right: 0;
    bottom: 0;
    width: min(100%, 400px);
    max-width: 100%;
    z-index: 40;
    transform: translateX(100%);
    transition: transform 0.28s cubic-bezier(0.22, 1, 0.36, 1);
    box-shadow: -12px 0 40px oklch(0.35 0.04 180 / 0.15);
    border-left: 1px solid var(--line);
  }

  .rail.is-open {
    transform: translateX(0);
  }

  .rail-overlay {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 35;
    background: oklch(0.2 0.04 180 / 0.35);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s ease;
  }

  .rail-overlay.is-visible {
    opacity: 1;
    pointer-events: auto;
  }

  .canvas-col {
    padding-bottom: 120px;
  }

  .watermark-preview {
    width: min(100px, 28%);
    bottom: 8px;
    right: 8px;
  }
}

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

  html {
    scroll-behavior: auto;
  }
}