/* ------------------------------------------------------------------ */
/* Design tokens — dark editorial system (Resend-inspired)             */
/* Pure black canvas, off-white ink, hairline borders instead of       */
/* shadows/blur, one atmospheric glow, a serif display headline.       */
/* ------------------------------------------------------------------ */

:root {
  color-scheme: dark;

  --canvas: #000000;
  --surface-card: #0a0a0c;
  --surface-elevated: #101012;
  --surface-deep: #06060a;

  --ink: #fcfdff;
  --body-c: rgba(252, 253, 255, 0.86);
  --charcoal: rgba(252, 253, 255, 0.7);
  --mute: #a1a4a5;
  --ash: #888e90;
  --stone: #464a4d;

  --hairline: rgba(255, 255, 255, 0.06);
  --hairline-strong: rgba(255, 255, 255, 0.14);
  --divider-soft: rgba(255, 255, 255, 0.04);

  --primary: #fcfdff;
  --primary-on: #000000;
  --primary-pressed: #f1f7fe;

  --accent-orange: #ff801f;
  --accent-orange-glow: rgba(255, 89, 0, 0.22);
  --accent-yellow: #ffc53d;
  --accent-blue: #3b9eff;
  --accent-blue-glow: rgba(0, 117, 255, 0.34);
  --accent-green: #11ff99;
  --accent-green-glow: rgba(34, 255, 153, 0.18);
  --accent-red: #ff2047;
  --accent-red-glow: rgba(255, 32, 71, 0.34);

  --radius-none: 0px;
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);

  --font-serif: ui-serif, "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink);
  font-family: var(--font-sans);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ------------------------------------------------------------------ */
/* Nav bar                                                              */
/* ------------------------------------------------------------------ */

.nav-bar {
  position: sticky;
  top: 0;
  z-index: 20;
  height: 64px;
  background: var(--canvas);
  border-bottom: 1px solid var(--hairline);
}

.nav-inner {
  max-width: 1000px;
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.wordmark {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.wordmark-sm {
  font-size: 0.95rem;
}

.badge-pill {
  background: var(--surface-elevated);
  color: var(--body-c);
  font-size: 0.75rem;
  line-height: 1.5;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  border: 1px solid var(--hairline-strong);
  white-space: nowrap;
}

/* ------------------------------------------------------------------ */
/* Layout                                                               */
/* ------------------------------------------------------------------ */

.layout {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px 96px;
}

/* ------------------------------------------------------------------ */
/* Hero                                                                 */
/* ------------------------------------------------------------------ */

.hero {
  position: relative;
  padding: 96px 0 48px;
  text-align: center;
  isolation: isolate;
}

.hero-glow {
  position: absolute;
  top: -160px;
  left: 50%;
  width: 760px;
  height: 460px;
  transform: translateX(-50%);
  background: radial-gradient(ellipse at center, var(--accent-blue-glow) 0%, transparent 70%);
  filter: blur(70px);
  opacity: 0;
  animation: glow-in 1.1s var(--ease) 0.1s forwards;
  pointer-events: none;
  z-index: -1;
}

@keyframes glow-in {
  to { opacity: 0.55; }
}

@media (prefers-reduced-motion: reduce) {
  .hero-glow {
    animation: none;
    opacity: 0.55;
  }
}

.hero-title {
  margin: 0 0 20px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: clamp(2.25rem, 5.4vw, 3.5rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.hero-subtitle {
  margin: 0 auto;
  max-width: 480px;
  color: var(--charcoal);
  font-size: 1.05rem;
  line-height: 1.55;
}

/* ------------------------------------------------------------------ */
/* Upload card                                                         */
/* ------------------------------------------------------------------ */

.upload-card {
  background: var(--surface-card);
  border: 1px dashed var(--hairline-strong);
  border-radius: var(--radius-lg);
  padding: 44px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.upload-card.drag-active {
  border-color: var(--accent-blue);
  border-style: solid;
  background: color-mix(in srgb, var(--accent-blue) 6%, var(--surface-card));
}

.upload-title {
  margin: 0 0 6px;
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--ink);
}

.upload-sub {
  margin: 0 0 16px;
  color: var(--ash);
  font-size: 0.85rem;
}

/* ------------------------------------------------------------------ */
/* Buttons                                                              */
/* ------------------------------------------------------------------ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 36px;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s var(--ease), border-color 0.15s var(--ease), color 0.15s var(--ease), opacity 0.15s var(--ease);
}

.btn-primary {
  background: var(--primary);
  color: var(--primary-on);
}

@media (hover: hover) {
  .btn-primary:hover { background: var(--primary-pressed); }
}

.btn-primary:active {
  background: var(--primary-pressed);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: default;
}

.btn-ghost {
  background: var(--surface-elevated);
  color: var(--ink);
  border-color: var(--hairline-strong);
}

@media (hover: hover) {
  .btn-ghost:hover { border-color: rgba(255, 255, 255, 0.3); }
}

.btn-outline {
  background: var(--canvas);
  color: var(--ink);
  border-color: var(--hairline-strong);
}

@media (hover: hover) {
  .btn-outline:hover { background: var(--surface-card); border-color: rgba(255, 255, 255, 0.3); }
}

.btn-danger {
  background: transparent;
  color: var(--accent-red);
  border-color: rgba(255, 32, 71, 0.35);
}

@media (hover: hover) {
  .btn-danger:hover { background: rgba(255, 32, 71, 0.12); border-color: var(--accent-red); }
}

.btn-sm {
  height: 30px;
  padding: 5px 12px;
  font-size: 0.8rem;
}

.btn-lg {
  height: 44px;
  padding: 11px 22px;
  font-size: 0.92rem;
}

/* ------------------------------------------------------------------ */
/* File bar / messages                                                 */
/* ------------------------------------------------------------------ */

.file-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background: var(--surface-card);
  border: 1px solid var(--hairline-strong);
  border-radius: var(--radius-lg);
  padding: 14px 18px;
  margin-top: 20px;
}

.file-bar-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  flex: 1 1 auto;
}

.file-name {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 400;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
}

#file-size {
  white-space: nowrap;
}

@media (max-width: 520px) {
  .file-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .file-bar .btn {
    width: 100%;
  }
}

.status-dot {
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  background: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green-glow);
}

.muted {
  color: var(--mute);
  font-size: 0.82rem;
}

.messages {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.message {
  padding: 12px 16px;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  background: color-mix(in srgb, var(--accent-orange) 8%, var(--surface-card));
  border: 1px solid var(--hairline-strong);
  border-left: 3px solid var(--accent-orange);
  color: var(--body-c);
}

/* ------------------------------------------------------------------ */
/* Editor shell + tabs                                                 */
/* ------------------------------------------------------------------ */

.editor-shell {
  margin-top: 24px;
  background: var(--surface-card);
  border: 1px solid var(--hairline-strong);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.tabs {
  position: relative;
  display: flex;
  gap: 2px;
  margin: 14px;
  padding: 4px;
  border-radius: var(--radius-full);
  background: var(--canvas);
  border: 1px solid var(--hairline);
  overflow-x: auto;
  scrollbar-width: none;
}

.tabs::-webkit-scrollbar {
  display: none;
}

.tab-indicator {
  position: absolute;
  top: 4px;
  bottom: 4px;
  left: 4px;
  width: 0;
  border-radius: var(--radius-full);
  background: var(--surface-elevated);
  border: 1px solid var(--hairline-strong);
  transition: transform 0.32s var(--ease), width 0.32s var(--ease);
  will-change: transform, width;
  z-index: 0;
}

.tab-btn {
  position: relative;
  z-index: 1;
  flex: none;
  white-space: nowrap;
  background: transparent;
  border: none;
  border-radius: var(--radius-full);
  padding: 9px 16px;
  cursor: pointer;
  color: var(--charcoal);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  transition: color 0.2s var(--ease);
}

.tab-btn.active {
  color: var(--ink);
}

.tab-panel {
  padding: 8px 20px 20px;
}

.panel-hint {
  color: var(--ash);
  margin-top: 0;
  font-size: 0.85rem;
}

.prop-form {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px 18px;
}

.form-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--ash);
}

.form-row input {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--ink);
  background: var(--surface-elevated);
  border: 1px solid var(--hairline-strong);
  border-radius: var(--radius-md);
  padding: 10px 12px;
  height: 40px;
  transition: border-color 0.15s var(--ease);
}

.form-row input:focus {
  outline: none;
  border-color: var(--ink);
}

.info-box {
  margin-top: 18px;
  padding: 11px 15px;
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--accent-blue) 8%, var(--surface-elevated));
  border: 1px solid var(--hairline-strong);
  border-left: 3px solid var(--accent-blue);
  font-size: 0.83rem;
  color: var(--body-c);
}

/* ------------------------------------------------------------------ */
/* Checkpoints table                                                    */
/* ------------------------------------------------------------------ */

.checkpoints-toolbar {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--hairline);
}

.checkpoints-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  background: var(--surface-deep);
}

.checkpoints-table th,
.checkpoints-table td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--hairline);
  vertical-align: top;
}

.checkpoints-table th {
  color: var(--ash);
  font-weight: 500;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--surface-card);
}

.checkpoints-table tbody tr {
  animation: row-in 0.3s var(--ease) both;
  transition: background 0.15s var(--ease);
}

@media (hover: hover) {
  .checkpoints-table tbody tr:hover {
    background: var(--divider-soft);
  }
}

@keyframes row-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .checkpoints-table tbody tr,
  .message {
    animation: none !important;
  }
}

.actions-cell {
  display: flex;
  gap: 6px;
  white-space: nowrap;
}

#checkpoints-empty {
  margin-top: 10px;
}

/* ------------------------------------------------------------------ */
/* Download bar                                                        */
/* ------------------------------------------------------------------ */

.download-bar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 20px;
  border-top: 1px solid var(--hairline);
  background: var(--surface-elevated);
}

/* ------------------------------------------------------------------ */
/* Dialog                                                               */
/* ------------------------------------------------------------------ */

dialog {
  border: 1px solid var(--hairline-strong);
  border-radius: var(--radius-lg);
  padding: 0;
  background: var(--surface-elevated);
  color: var(--ink);
  max-width: 460px;
  width: calc(100% - 40px);
}

dialog[open] {
  animation: dialog-in 0.22s var(--ease) both;
}

dialog.closing {
  animation: dialog-out 0.16s var(--ease) forwards;
}

@keyframes dialog-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes dialog-out {
  to { opacity: 0; transform: translateY(6px); }
}

dialog::backdrop {
  background: rgba(0, 0, 0, 0.7);
  animation: backdrop-in 0.22s var(--ease) both;
}

dialog.closing::backdrop {
  animation: backdrop-out 0.16s var(--ease) forwards;
}

@keyframes backdrop-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes backdrop-out {
  to { opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  dialog[open], dialog.closing, dialog::backdrop, dialog.closing::backdrop {
    animation: none !important;
  }
}

.checkpoint-form {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.checkpoint-form h2 {
  margin: 0 0 4px;
  font-family: var(--font-serif);
  font-weight: 400;
  font-size: 1.35rem;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.checkpoint-form label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--ash);
}

.checkpoint-form input,
.checkpoint-form textarea {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--ink);
  background: var(--surface-card);
  border: 1px solid var(--hairline-strong);
  border-radius: var(--radius-md);
  padding: 9px 12px;
  resize: vertical;
  transition: border-color 0.15s var(--ease);
}

.checkpoint-form input:focus,
.checkpoint-form textarea:focus {
  outline: none;
  border-color: var(--ink);
}

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 6px;
}

/* ------------------------------------------------------------------ */
/* Footer                                                               */
/* ------------------------------------------------------------------ */

.footer {
  border-top: 1px solid var(--divider-soft);
  padding: 40px 20px;
}

.footer-inner {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ash);
  font-size: 0.82rem;
}

.footer-inner p {
  margin: 0;
}

/* ------------------------------------------------------------------ */
/* Fine print                                                          */
/* ------------------------------------------------------------------ */

code {
  font-family: var(--font-mono);
  background: var(--surface-elevated);
  color: var(--body-c);
  padding: 1px 5px;
  border-radius: var(--radius-xs);
  font-size: 0.85em;
  border: 1px solid var(--hairline);
}