/* ==========================================================================
   THE STACKS — Reading Log
   Warm literary editorial aesthetic
   ========================================================================== */

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

:root {
  /* Warm paper backgrounds */
  --bg: #FAF6F0;
  --bg-surface: #FFFFFF;
  --bg-warm: #F3EDE3;
  --bg-inset: #EDE7DC;
  --bg-hover: #F0E9DE;

  /* Warm text hierarchy */
  --text: #1C160F;
  --text-secondary: #5C4F42;
  --text-muted: #9C8E7E;
  --text-faint: #C4B8A8;

  /* Terracotta accent — warm, literary, earthy */
  --accent: #B84C2A;
  --accent-hover: #A03F20;
  --accent-light: rgba(184, 76, 42, 0.07);
  --accent-medium: rgba(184, 76, 42, 0.14);

  /* Status colors — muted, natural tones */
  --reading: #2E7D9B;
  --completed: #3D7C47;
  --want-to-read: #7C5BAD;
  --dnf: #B85450;
  --rated: #C08B24;
  --reread: #2E7D9B;

  /* Typography */
  --font-display: 'Fraunces', 'Georgia', serif;
  --font-body: 'Figtree', 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Menlo', monospace;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 36px;
  --space-2xl: 56px;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Shadows — warm, soft */
  --shadow-sm: 0 1px 3px rgba(28, 22, 15, 0.06);
  --shadow-md: 0 4px 12px rgba(28, 22, 15, 0.08);
  --shadow-lg: 0 8px 24px rgba(28, 22, 15, 0.1);
  --shadow-book: 2px 4px 12px rgba(28, 22, 15, 0.15);

  --transition: 0.2s ease;

  /* Topbar background (overridden in dark mode) */
  --topbar-bg: rgba(250, 246, 240, 0.92);
  --topbar-border: rgba(28, 22, 15, 0.08);
  --card-border: rgba(28, 22, 15, 0.04);
  --discord-bg: #5865F2;
}

/* --- Dark Mode --- */

[data-theme="dark"] {
  --bg: #111114;
  --bg-surface: #1a1a1f;
  --bg-warm: #1f1f26;
  --bg-inset: #26262e;
  --bg-hover: #2a2a34;

  --text: #e4e1da;
  --text-secondary: #a8a29e;
  --text-muted: #787068;
  --text-faint: #52493f;

  --accent: #D4724A;
  --accent-hover: #E0845C;
  --accent-light: rgba(212, 114, 74, 0.1);
  --accent-medium: rgba(212, 114, 74, 0.18);

  --reading: #4DA3C4;
  --completed: #5CA86A;
  --want-to-read: #9B7FCC;
  --dnf: #D06B68;
  --rated: #D9A83A;
  --reread: #4DA3C4;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-book: 2px 4px 12px rgba(0, 0, 0, 0.4);

  --topbar-bg: rgba(17, 17, 20, 0.92);
  --topbar-border: rgba(255, 255, 255, 0.06);
  --card-border: rgba(255, 255, 255, 0.04);

  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111114;
    --bg-surface: #1a1a1f;
    --bg-warm: #1f1f26;
    --bg-inset: #26262e;
    --bg-hover: #2a2a34;

    --text: #e4e1da;
    --text-secondary: #a8a29e;
    --text-muted: #787068;
    --text-faint: #52493f;

    --accent: #D4724A;
    --accent-hover: #E0845C;
    --accent-light: rgba(212, 114, 74, 0.1);
    --accent-medium: rgba(212, 114, 74, 0.18);

    --reading: #4DA3C4;
    --completed: #5CA86A;
    --want-to-read: #9B7FCC;
    --dnf: #D06B68;
    --rated: #D9A83A;
    --reread: #4DA3C4;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.35);
    --shadow-book: 2px 4px 12px rgba(0, 0, 0, 0.4);

    --topbar-bg: rgba(17, 17, 20, 0.92);
    --topbar-border: rgba(255, 255, 255, 0.06);
    --card-border: rgba(255, 255, 255, 0.04);

    color-scheme: dark;
  }
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

::selection {
  background: var(--accent-medium);
  color: var(--text);
}

/* --- Subtle paper texture --- */

.bg-texture {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.35;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
}

/* Hide old dark-theme background elements */
.bg-noise, .bg-glow, .bg-glow--1, .bg-glow--2 { display: none; }

/* --- Top Bar --- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  padding: var(--space-md) var(--space-xl);
  background: var(--topbar-bg);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--topbar-border);
}

.topbar__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-shrink: 0;
  text-decoration: none;
  color: inherit;
}

.topbar__brand:hover {
  text-decoration: none;
  opacity: 0.8;
}

.topbar__logo {
  color: var(--accent);
}

.topbar__brand-text {
  display: flex;
  flex-direction: column;
}

.topbar__title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
  font-variation-settings: 'opsz' 36;
}

.topbar__nav {
  display: flex;
  gap: 2px;
  flex: 1;
  justify-content: center;
}

.topbar__user {
  flex-shrink: 0;
}

.topbar__burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}

.topbar__burger span {
  display: block;
  width: 18px;
  height: 1.5px;
  background: var(--text-secondary);
  border-radius: 1px;
  transition: var(--transition);
}

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

.tab-btn {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-muted);
  background: none;
  border: none;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  letter-spacing: 0.01em;
  position: relative;
}

.tab-btn:hover {
  color: var(--text-secondary);
}

.tab-btn--active {
  color: var(--accent);
  font-weight: 600;
}

.tab-btn--active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: var(--space-md);
  right: var(--space-md);
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

/* --- Theme Toggle --- */

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: none;
  border: 1px solid var(--bg-inset);
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--text-muted);
  transition: var(--transition);
  flex-shrink: 0;
}

.theme-toggle:hover {
  color: var(--text);
  border-color: var(--text-muted);
}

/* In light mode, show moon (switch to dark). In dark mode, show sun (switch to light). */
.theme-toggle__moon { display: block; }
.theme-toggle__sun { display: none; }

[data-theme="dark"] .theme-toggle__moon { display: none; }
[data-theme="dark"] .theme-toggle__sun { display: block; }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle__moon { display: none; }
  :root:not([data-theme="light"]) .theme-toggle__sun { display: block; }
}

/* --- Login Button --- */

.login-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  color: #fff;
  background: #5865F2;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  white-space: nowrap;
}

.login-btn:hover {
  background: #4752c4;
  text-decoration: none;
}

/* --- User Badge --- */

.user-badge {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.user-badge__avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  object-fit: cover;
  border: 1.5px solid var(--bg-inset);
}

.user-badge__avatar--placeholder {
  background: var(--bg-inset);
}

.user-badge__name {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text);
}

.user-badge__action {
  font-size: 0.75rem;
  color: var(--accent);
  cursor: pointer;
  padding: 2px var(--space-sm);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  font-weight: 500;
}

.user-badge__action:hover {
  background: var(--accent-light);
}

.user-badge__logout {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-left: var(--space-xs);
}

/* --- Main & Panels --- */

.main {
  position: relative;
  z-index: 1;
  max-width: 960px;
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
  min-height: calc(100vh - 56px);
}

.panel {
  display: none;
  animation: fadeIn 0.35s ease;
}

.panel--active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.panel__header {
  margin-bottom: var(--space-xl);
}

.panel__title {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 500;
  color: var(--text);
  letter-spacing: -0.02em;
  font-variation-settings: 'opsz' 48;
}

.panel__subtitle {
  font-size: 0.9375rem;
  color: var(--text-muted);
  margin-top: var(--space-xs);
}

/* --- Loading & Empty States --- */

.loading {
  display: flex;
  justify-content: center;
  padding: var(--space-2xl);
}

.loading__spinner {
  width: 28px;
  height: 28px;
  border: 2.5px solid var(--bg-inset);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.75s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* --- Skeleton Loading --- */

@keyframes shimmer {
  0% { background-position: -400px 0; }
  100% { background-position: 400px 0; }
}

.loading-skeleton {
  padding: var(--space-lg) 0;
}

.skeleton {
  background: linear-gradient(90deg, var(--bg-inset) 25%, var(--bg-hover) 50%, var(--bg-inset) 75%);
  background-size: 800px 100%;
  animation: shimmer 1.5s ease infinite;
  border-radius: var(--radius-md);
}

.skeleton--bar {
  height: 20px;
  border-radius: var(--radius-sm);
}

.skeleton--card {
  height: 180px;
}

.skeleton-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.empty-state {
  text-align: center;
  padding: var(--space-2xl);
  color: var(--text-muted);
}

.empty-state__icon {
  font-size: 2rem;
  margin-bottom: var(--space-md);
  opacity: 0.3;
}

.empty-state__text {
  font-size: 0.9375rem;
  line-height: 1.5;
}

/* --- Auth Prompt --- */

.auth-prompt {
  text-align: center;
  padding: var(--space-2xl) var(--space-lg);
  max-width: 400px;
  margin: var(--space-2xl) auto;
}

.auth-prompt__icon {
  font-size: 2.5rem;
  color: var(--accent);
  opacity: 0.4;
  margin-bottom: var(--space-lg);
}

.auth-prompt h2 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 500;
  margin-bottom: var(--space-md);
  font-variation-settings: 'opsz' 36;
}

.auth-prompt p {
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
  font-size: 0.9375rem;
}

.auth-prompt__btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 600;
  color: #fff;
  background: #5865F2;
  padding: 10px var(--space-xl);
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.auth-prompt__btn:hover {
  background: #4752c4;
  text-decoration: none;
}

/* --- Buttons --- */

.btn {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: var(--space-sm) var(--space-md);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.btn--small {
  font-size: 0.75rem;
  padding: 4px 10px;
  color: var(--accent);
  background: var(--accent-light);
  border: 1px solid var(--accent-medium);
}

.btn--small:hover {
  background: var(--accent-medium);
}

.btn--ghost {
  color: var(--text-secondary);
  background: none;
  padding: var(--space-sm) var(--space-md);
}

.btn--ghost:hover {
  color: var(--text);
  background: var(--bg-warm);
}

/* --- Sub Tabs --- */

.sub-tabs {
  display: flex;
  gap: 0;
  margin-bottom: var(--space-lg);
  border-bottom: 1px solid var(--bg-inset);
  overflow-x: auto;
  mask-image: linear-gradient(to right, black calc(100% - 24px), transparent 100%);
  -webkit-mask-image: linear-gradient(to right, black calc(100% - 24px), transparent 100%);
}

/* Remove scroll fade when not overflowing (desktop) */
@media (min-width: 769px) {
  .sub-tabs {
    mask-image: none;
    -webkit-mask-image: none;
  }
}

.sub-tab {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-muted);
  background: none;
  border: none;
  padding: var(--space-sm) var(--space-md) 10px;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
}

.sub-tab:hover {
  color: var(--text-secondary);
}

.sub-tab--active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

.sub-tab__count {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  color: var(--text-faint);
  margin-left: 4px;
}

/* --- Scroll to top --- */

.scroll-top-btn {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-surface);
  border: 1px solid var(--bg-inset);
  color: var(--text-secondary);
  font-size: 1.125rem;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  z-index: 50;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.25s ease, transform 0.25s ease, background 0.2s ease;
  pointer-events: none;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.scroll-top-btn--visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.scroll-top-btn:hover {
  background: var(--accent-light);
  border-color: var(--accent-medium);
  color: var(--accent);
}