/* Foroba — Stylesheet refonte
 * Landing : sombre (blanc sur noir)
 * App     : clair (noir sur blanc)
 * Accent  : cobalt (parcourt les deux)
 * Type    : Instrument Serif (display) + Geist (body) + Geist Mono (utility)
 */

/* ---------- Tokens ---------- */
:root {
  --black: #0a0a0a;
  --ink: #111418;
  --paper: #fbfaf6;
  --paper-warm: #f3f1ea;
  --line: #e7e3d6;
  --line-dark: #1f242b;
  --mute: #6b7177;
  --mute-dark: #8a8f97;
  --cobalt: #2456e3;
  --cobalt-bright: #4a7aff;
  --signal: #ff5a1f;

  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'Geist', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', sans-serif;
  --font-mono: 'Geist Mono', ui-monospace, 'SF Mono', monospace;

  --radius: 4px;
  --radius-lg: 10px;
}

/* ---------- Reset ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }
input, textarea { font: inherit; color: inherit; }
img, svg { display: block; max-width: 100%; }

/* ---------- LANDING (mode sombre) ---------- */
body.landing {
  background: var(--black);
  color: var(--paper);
}

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 28px;
}

.site-header {
  padding: 28px 0;
  border-bottom: 1px solid var(--line-dark);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 400;
  letter-spacing: -0.02em;
  font-style: italic;
}
.brand-dot { color: var(--cobalt-bright); font-style: normal; }
.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.site-nav a {
  color: var(--mute-dark);
  transition: color 0.15s;
}
.site-nav a:hover { color: var(--paper); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  border-radius: 999px;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 14px;
  letter-spacing: -0.005em;
  transition: all 0.18s ease;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
}
.btn-primary {
  background: var(--paper);
  color: var(--black);
}
.btn-primary:hover {
  background: var(--cobalt-bright);
  color: var(--paper);
  transform: translateY(-1px);
}
.btn-ghost {
  background: transparent;
  color: var(--paper);
  border-color: rgba(255,255,255,0.18);
}
.btn-ghost:hover {
  border-color: var(--paper);
  background: rgba(255,255,255,0.04);
}
.btn-cobalt {
  background: var(--cobalt);
  color: var(--paper);
}
.btn-cobalt:hover { background: var(--cobalt-bright); }
.btn-block { width: 100%; padding: 16px 22px; font-size: 15px; }
.btn-lg { padding: 16px 28px; font-size: 15px; }

/* HERO */
.hero {
  padding: 100px 0 80px;
  position: relative;
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}
@media (min-width: 900px) {
  .hero-grid { grid-template-columns: 1fr auto; gap: 80px; }
}

.hero-mark {
  display: none;
}
@media (min-width: 900px) {
  .hero-mark {
    display: block;
    width: 280px;
    height: 280px;
  }
  .hero-mark svg {
    width: 100%;
    height: 100%;
    display: block;
  }
}

.hero-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mute-dark);
  margin-bottom: 28px;
  display: inline-flex;
  align-items: center;
  gap: 12px;
}
.hero-label::before {
  content: "";
  display: inline-block;
  width: 28px;
  height: 1px;
  background: var(--mute-dark);
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(96px, 18vw, 220px);
  line-height: 0.88;
  letter-spacing: -0.04em;
  font-weight: 400;
  font-style: italic;
  color: var(--paper);
  margin-bottom: 0;
}
.hero-title .dot {
  color: var(--cobalt-bright);
  font-style: normal;
}

.hero-aside { padding-bottom: 8px; }
.hero-def { border-top: 1px solid var(--line-dark); padding-top: 18px; }
.hero-def-row {
  display: flex;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line-dark);
  font-size: 14px;
}
.hero-def-row:last-child { border-bottom: none; }
.hero-def-key {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mute-dark);
  min-width: 80px;
  padding-top: 3px;
}
.hero-def-val {
  flex: 1;
  color: var(--paper);
  font-size: 15px;
  line-height: 1.5;
}
.hero-def-val em {
  font-family: var(--font-display);
  font-style: italic;
  color: var(--cobalt-bright);
}

.hero-tagline {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.25;
  font-weight: 400;
  letter-spacing: -0.015em;
  color: var(--paper);
  max-width: 720px;
  margin-top: 48px;
}
.hero-tagline em { font-style: italic; color: var(--cobalt-bright); }

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 40px;
}

.section {
  padding: 100px 0;
  border-top: 1px solid var(--line-dark);
}
.section-num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mute-dark);
  margin-bottom: 32px;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(40px, 6vw, 68px);
  line-height: 1.05;
  font-weight: 400;
  font-style: italic;
  letter-spacing: -0.025em;
  max-width: 880px;
  margin-bottom: 28px;
}
.section-title .accent { color: var(--cobalt-bright); font-style: italic; }
.section-body {
  font-size: 18px;
  color: var(--mute-dark);
  max-width: 640px;
  line-height: 1.6;
}

.examples {
  margin-top: 56px;
  border-top: 1px solid var(--line-dark);
}
.example {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  padding: 32px 0;
  border-bottom: 1px solid var(--line-dark);
}
@media (min-width: 720px) {
  .example {
    grid-template-columns: 80px 1fr 1fr;
    gap: 40px;
    align-items: baseline;
  }
}
.example-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mute-dark);
}
.example-q {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 22px;
  line-height: 1.3;
  color: var(--paper);
}
.example-a {
  font-size: 15px;
  color: var(--mute-dark);
  line-height: 1.6;
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-top: 32px;
}
@media (min-width: 900px) {
  .about-grid { grid-template-columns: 280px 1fr; gap: 80px; }
}
.about-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mute-dark);
}
.about-text {
  font-size: 19px;
  color: var(--paper);
  line-height: 1.55;
}
.about-text em {
  font-family: var(--font-display);
  font-style: italic;
  color: var(--cobalt-bright);
  font-size: 1.05em;
}

.cta {
  padding: 120px 0;
  border-top: 1px solid var(--line-dark);
  text-align: center;
}
.cta-title {
  font-family: var(--font-display);
  font-style: italic;
  font-size: clamp(44px, 8vw, 88px);
  line-height: 1;
  letter-spacing: -0.03em;
  margin-bottom: 40px;
}
.cta-title .dot { color: var(--cobalt-bright); font-style: normal; }

.site-footer {
  padding: 40px 0;
  border-top: 1px solid var(--line-dark);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--mute-dark);
}
.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 20px;
}
.site-footer a { color: var(--mute-dark); }
.site-footer a:hover { color: var(--paper); }

/* Auth panel */
.auth-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
  z-index: 100;
}
.auth-overlay.open { display: flex; }
.auth-panel {
  background: var(--ink);
  border: 1px solid var(--line-dark);
  border-radius: var(--radius-lg);
  max-width: 440px;
  width: 100%;
  padding: 40px;
  position: relative;
}
.auth-title {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 38px;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
  color: var(--paper);
}
.auth-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mute-dark);
  margin-bottom: 32px;
}
.field { margin-bottom: 18px; }
.field label {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mute-dark);
  margin-bottom: 8px;
}
.field input {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--line-dark);
  border-radius: var(--radius);
  background: var(--black);
  color: var(--paper);
  font-size: 15px;
  font-family: var(--font-body);
  transition: border-color 0.15s;
}
.field input:focus {
  outline: none;
  border-color: var(--cobalt-bright);
}
.auth-toggle {
  text-align: center;
  margin-top: 20px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mute-dark);
}
.auth-toggle button {
  color: var(--cobalt-bright);
  text-decoration: underline;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.auth-error {
  background: rgba(255, 90, 31, 0.1);
  color: var(--signal);
  border: 1px solid rgba(255, 90, 31, 0.3);
  padding: 12px 14px;
  border-radius: var(--radius);
  font-size: 14px;
  margin-bottom: 18px;
  display: none;
}
.auth-error.show { display: block; }
.auth-close {
  position: absolute;
  top: 16px;
  right: 16px;
  font-size: 28px;
  color: var(--mute-dark);
  line-height: 1;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-weight: 300;
}
.auth-close:hover { color: var(--paper); }

/* ---------- APP — mode clair ---------- */
body.app {
  background: var(--paper);
  color: var(--ink);
  overflow: hidden;
}

.app-shell {
  display: grid;
  grid-template-columns: 280px 1fr;
  height: 100dvh;
}

@media (max-width: 768px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 280px;
    z-index: 50;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    box-shadow: 0 0 40px rgba(0,0,0,0.15);
  }
  .sidebar.open { transform: translateX(0); }
  .sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(10,10,10,0.4);
    z-index: 40;
    display: none;
  }
  .sidebar-overlay.show { display: block; }
}

.sidebar {
  background: var(--paper-warm);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.sidebar-header {
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
}
.sidebar-brand {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 24px;
  color: var(--ink);
  letter-spacing: -0.02em;
}
.sidebar-brand .dot { color: var(--cobalt); font-style: normal; }

.new-chat-btn {
  width: calc(100% - 32px);
  margin: 16px 16px 8px;
  padding: 12px 14px;
  background: var(--cobalt);
  color: var(--paper);
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: -0.005em;
  transition: background 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.new-chat-btn:hover { background: var(--cobalt-bright); }
.new-chat-btn::before { content: "+"; font-size: 18px; font-weight: 400; }

.conv-section-label {
  padding: 14px 20px 8px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--mute);
}

.conv-list {
  flex: 1;
  overflow-y: auto;
  padding: 0 8px 16px;
}

.conv-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--ink);
  cursor: pointer;
  text-align: left;
  transition: background 0.12s;
  margin-bottom: 2px;
  gap: 8px;
}
.conv-item:hover { background: rgba(36, 86, 227, 0.06); }
.conv-item.active {
  background: rgba(36, 86, 227, 0.1);
  color: var(--cobalt);
  font-weight: 500;
}
.conv-title {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.conv-delete {
  opacity: 0;
  font-size: 16px;
  color: var(--mute);
  padding: 2px 6px;
  border-radius: 4px;
  transition: opacity 0.12s, color 0.12s;
  flex-shrink: 0;
}
.conv-item:hover .conv-delete { opacity: 0.7; }
.conv-delete:hover { opacity: 1 !important; color: var(--signal); background: rgba(255, 90, 31, 0.08); }

.conv-empty {
  padding: 12px 20px;
  font-size: 13px;
  color: var(--mute);
  font-style: italic;
}

.sidebar-footer {
  padding: 14px 20px;
  border-top: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 12px;
}
.user-email {
  color: var(--mute);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
  font-family: var(--font-mono);
  font-size: 11px;
}
.logout-btn {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mute);
  flex-shrink: 0;
}
.logout-btn:hover { color: var(--signal); }

.main {
  display: flex;
  flex-direction: column;
  background: var(--paper);
  overflow: hidden;
  min-width: 0;
}

.main-header {
  padding: 14px 24px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
  background: var(--paper);
}
.menu-toggle {
  display: none;
  font-size: 20px;
  padding: 6px 10px;
  color: var(--ink);
}
@media (max-width: 768px) {
  .menu-toggle { display: block; }
}

.conv-title-display {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 18px;
  color: var(--ink);
  flex: 1;
  margin: 0 16px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.quota-pill {
  background: rgba(36, 86, 227, 0.08);
  color: var(--cobalt);
  padding: 5px 12px;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  flex-shrink: 0;
}
.quota-pill.exhausted {
  background: rgba(255, 90, 31, 0.1);
  color: var(--signal);
}

.banner {
  background: rgba(36, 86, 227, 0.06);
  border-bottom: 1px solid rgba(36, 86, 227, 0.2);
  padding: 12px 24px;
  font-size: 13px;
  text-align: center;
  color: var(--cobalt);
  display: none;
}
.banner.show { display: block; }
.banner.warn {
  background: rgba(255, 90, 31, 0.06);
  border-color: rgba(255, 90, 31, 0.2);
  color: var(--signal);
}

.chat-area {
  flex: 1;
  overflow-y: auto;
  padding: 32px 0;
}
.chat-stream {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 24px;
}

.msg { margin-bottom: 32px; }
.msg-role {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 8px;
  color: var(--mute);
}
.msg-user .msg-role { color: var(--ink); }
.msg-assistant .msg-role { color: var(--cobalt); }
.msg-content {
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink);
  white-space: pre-wrap;
  word-wrap: break-word;
}

.chat-empty {
  text-align: center;
  padding: 80px 24px;
}
.chat-empty-title {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 48px;
  line-height: 1;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin-bottom: 16px;
}
.chat-empty-title .dot { color: var(--cobalt); font-style: normal; }
.chat-empty-sub {
  font-size: 15px;
  color: var(--mute);
  max-width: 420px;
  margin: 0 auto 32px;
}

.suggested-prompts {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  max-width: 520px;
  margin: 0 auto;
}
@media (min-width: 600px) {
  .suggested-prompts { grid-template-columns: 1fr 1fr; }
}
.suggested-prompt {
  text-align: left;
  padding: 14px 16px;
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 13px;
  color: var(--ink);
  line-height: 1.4;
  transition: all 0.15s;
  cursor: pointer;
}
.suggested-prompt:hover {
  border-color: var(--cobalt);
  color: var(--cobalt);
  background: rgba(36, 86, 227, 0.04);
}

.composer {
  border-top: 1px solid var(--line);
  background: var(--paper);
  padding: 16px 24px 20px;
  flex-shrink: 0;
}
.composer-inner {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  gap: 10px;
  align-items: flex-end;
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 6px;
  transition: border-color 0.15s;
}
.composer-inner:focus-within {
  border-color: var(--cobalt);
}
.composer textarea {
  flex: 1;
  border: none;
  background: transparent;
  padding: 10px 12px;
  font-size: 15px;
  resize: none;
  min-height: 40px;
  max-height: 180px;
  font-family: var(--font-body);
  color: var(--ink);
}
.composer textarea:focus { outline: none; }
.send-btn {
  background: var(--cobalt);
  color: var(--paper);
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 13px;
  font-weight: 500;
  transition: background 0.15s;
  flex-shrink: 0;
  align-self: stretch;
}
.send-btn:hover:not(:disabled) { background: var(--cobalt-bright); }
.send-btn:disabled {
  background: var(--line);
  color: var(--mute);
  cursor: not-allowed;
}

.typing-dots {
  display: inline-flex;
  gap: 4px;
  align-items: center;
  color: var(--cobalt);
}
.typing-dots span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  animation: pulse 1.4s infinite ease-in-out;
}
.typing-dots span:nth-child(2) { animation-delay: 0.2s; }
.typing-dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes pulse {
  0%, 60%, 100% { opacity: 0.3; transform: scale(0.8); }
  30% { opacity: 1; transform: scale(1); }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}