/* ==========================================================================
   SATRIA — styles
   Material "Liquid Glass": panel kaca tembus pandang (blur + saturasi),
   border putih halus, sorotan tepi atas, bayangan lembut. Kaca dipakai pada
   navigasi, sidebar, toolbar, switcher tema, dan kolom input; konten utama
   tetap polos agar mudah dibaca. Tanpa gradient. Mobile-first.
   ========================================================================== */

/* ---------- Tokens ---------- */
:root {
  --font: "Poppins", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-brand: "Unbounded", "Poppins", sans-serif;   /* khusus kata SATRIA */
  --ease: cubic-bezier(.32, .72, 0, 1);   /* kurva halus ala iOS */
  --dur: .4s;

  --r-sm: 12px;
  --r: 14px;
  --r-lg: 20px;
  --r-xl: 24px;
  --pill: 9999px;
  --tap: 44px;
  --content-w: 760px;

  --sb-expanded: 284px;
  --sb-compact: 80px;
  --blur: blur(24px) saturate(180%);
}

/* Tema gelap (default) */
:root,
[data-theme="dark"] {
  --bg: #000000;
  --text: #f5f7fa;
  --text-2: #a7b0c0;
  --text-3: #8791a3;

  --glass: rgba(255, 255, 255, .07);
  --glass-hover: rgba(255, 255, 255, .1);
  --glass-strong: rgba(17, 24, 39, .78);
  --glass-fallback: rgba(22, 27, 38, .96);
  --glass-border: rgba(255, 255, 255, .12);
  --glass-hi: rgba(255, 255, 255, .1);
  --glass-shadow: 0 16px 48px rgba(0, 0, 0, .5), 0 2px 8px rgba(0, 0, 0, .35);

  --field: rgba(255, 255, 255, .05);
  --line: rgba(255, 255, 255, .1);
  --hover: rgba(255, 255, 255, .08);
  --thumb: rgba(255, 255, 255, .16);

  --accent: #7cb7ff;
  --accent-strong: #60a5fa;
  --accent-ink: #03101f;
  --accent-soft: rgba(96, 165, 250, .16);
  --accent-ring: rgba(96, 165, 250, .22);
  --accent-edge: rgba(124, 183, 255, .55);

  --overlay: rgba(0, 0, 0, .5);
  color-scheme: dark;
}

/* Tema terang: kaca putih yang ringan di atas abu-abu sejuk */
[data-theme="light"] {
  --bg: #eef1f6;
  --text: #0b1220;
  --text-2: #475266;
  --text-3: #5b667a;

  --glass: rgba(255, 255, 255, .62);
  --glass-hover: rgba(255, 255, 255, .8);
  --glass-strong: rgba(255, 255, 255, .82);
  --glass-fallback: rgba(255, 255, 255, .97);
  --glass-border: rgba(15, 23, 42, .08);
  --glass-hi: rgba(255, 255, 255, .9);
  --glass-shadow: 0 16px 40px rgba(15, 23, 42, .1), 0 1px 3px rgba(15, 23, 42, .06);

  --field: rgba(255, 255, 255, .75);
  --line: rgba(15, 23, 42, .1);
  --hover: rgba(15, 23, 42, .05);
  --thumb: #ffffff;

  --accent: #1d5fd6;
  --accent-strong: #2563eb;
  --accent-ink: #ffffff;
  --accent-soft: rgba(37, 99, 235, .12);
  --accent-ring: rgba(37, 99, 235, .18);
  --accent-edge: rgba(37, 99, 235, .45);

  --overlay: rgba(15, 23, 42, .25);
  color-scheme: light;
}

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

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; -webkit-tap-highlight-color: transparent; }

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.55;
  letter-spacing: -.006em;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

h1, h2, p { margin: 0; }
a { color: inherit; }
button, input, textarea { font: inherit; color: inherit; letter-spacing: inherit; }
button { cursor: pointer; }
[hidden] { display: none !important; }

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 10px;
}

.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }

.icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 100;
  padding: 8px 16px;
  border-radius: var(--pill);
  background: var(--accent-strong);
  color: var(--accent-ink);
  font-weight: 600;
  text-decoration: none;
  transform: translateY(-200%);
}
.skip-link:focus-visible { transform: none; }

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

/* ---------- Material kaca ---------- */
.glass {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-hi);
  -webkit-backdrop-filter: var(--blur);
  backdrop-filter: var(--blur);
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
/* Fallback: tanpa dukungan blur, pakai permukaan hampir solid agar teks tetap terbaca */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .glass { background: var(--glass-fallback); }
}

/* ---------- Primitif ---------- */
.wordmark,
.brand {
  font-family: var(--font-brand);
  font-weight: 700;
  letter-spacing: .02em;
}
.wordmark { font-size: 17px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 0 22px;
  border-radius: var(--pill);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: background-color .25s var(--ease), border-color .25s var(--ease), transform .25s var(--ease), opacity .25s var(--ease);
}
.btn .icon { width: 17px; height: 17px; }
.btn-block { width: 100%; }
.btn:active:not(:disabled) { transform: scale(.98); }

.btn-primary { background: var(--accent-strong); color: var(--accent-ink); }
.btn-primary:hover:not(:disabled) { background: var(--accent); }

.btn-glass {
  background: var(--glass);
  border-color: var(--glass-border);
  box-shadow: inset 0 1px 0 var(--glass-hi);
  color: var(--text);
}
.btn-glass:hover { background: var(--glass-hover); }

.btn:disabled { cursor: not-allowed; opacity: .42; }

.icon-btn {
  display: inline-grid;
  place-items: center;
  flex-shrink: 0;
  width: var(--tap);
  height: var(--tap);
  border-radius: var(--r);
  border: 0;
  background: transparent;
  color: var(--text-2);
  transition: background-color .25s var(--ease), color .25s var(--ease);
}
.icon-btn:hover { background: var(--hover); color: var(--text); }
.icon-btn .icon { transition: transform var(--dur) var(--ease); }

/* Switcher tema bersegmen dengan "thumb" yang bergeser */
.theme-switch {
  position: relative;
  display: inline-grid;
  grid-template-columns: 1fr 1fr;
  flex-shrink: 0;
  padding: 3px;
  border-radius: var(--pill);
  border: 1px solid var(--glass-border);
  background: var(--field);
}
.theme-switch::before {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  width: calc(50% - 3px);
  height: calc(100% - 6px);
  border-radius: var(--pill);
  background: var(--thumb);
  box-shadow: 0 1px 4px rgba(0, 0, 0, .25), inset 0 1px 0 var(--glass-hi);
  transition: transform var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
[data-theme="light"] .theme-switch::before { transform: translateX(100%); }
.theme-switch button {
  position: relative;
  display: grid;
  place-items: center;
  width: 38px;
  height: 36px;
  border: 0;
  border-radius: var(--pill);
  background: transparent;
  color: var(--text-3);
  transition: color .25s var(--ease);
}
.theme-switch button:hover,
.theme-switch button[aria-pressed="true"] { color: var(--text); }
.theme-switch .icon { width: 17px; height: 17px; }

/* ==========================================================================
   LOGIN
   ========================================================================== */
.view-login {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100dvh;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 12px 14px 0;
  padding-left: max(14px, env(safe-area-inset-left));
  padding-right: max(14px, env(safe-area-inset-right));
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  max-width: 1080px;
  margin: 0 auto;
  padding: 7px 7px 7px 20px;
  border-radius: var(--r-lg);
}

.login {
  flex: 1;
  display: grid;
  gap: 32px;
  align-content: center;
  width: 100%;
  max-width: 460px;
  margin: 0 auto;
  padding: 44px 18px 24px;
}
.login:focus { outline: none; }

.login-intro { display: grid; gap: 14px; }

.login-title {
  font-size: clamp(32px, 8.4vw, 48px);
  line-height: 1.25;   /* jarak antarbaris lebih longgar agar mudah dibaca */
  font-weight: 700;
  letter-spacing: -.03em;
  text-wrap: pretty;
}
.login-subtitle {
  font-size: clamp(16px, 2vw, 19px);
  font-weight: 450;
  line-height: 1.5;
  letter-spacing: -.012em;
  color: var(--text-2);
  max-width: 34ch;
}
.login-card {
  padding: 26px 22px;
  border-radius: var(--r-xl);
}
.login-card-title { font-size: 22px; font-weight: 650; letter-spacing: -.025em; line-height: 1.25; }
.login-card-sub { margin-top: 4px; font-size: 14px; color: var(--text-2); }

.login-form { display: grid; gap: 18px; margin-top: 24px; }

.field label {
  display: block;
  margin-bottom: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
}
.input-wrap { position: relative; display: flex; align-items: center; }
.input-wrap .icon {
  position: absolute;
  left: 16px;
  width: 17px;
  height: 17px;
  color: var(--text-3);
  pointer-events: none;
  transition: color .25s var(--ease);
}
.input-wrap input {
  width: 100%;
  min-height: 50px;
  padding: 0 16px 0 46px;
  border-radius: var(--r);
  border: 1px solid var(--line);
  background: var(--field);
  font-size: 16px; /* cegah auto-zoom iOS */
  transition: border-color .25s var(--ease), box-shadow .25s var(--ease), background-color .25s var(--ease);
}
.input-wrap input::placeholder { color: var(--text-3); opacity: .8; }
.input-wrap input:hover { border-color: var(--glass-border); background: var(--glass); }
.input-wrap input:focus-visible {
  outline: none;
  border-color: var(--accent-edge);
  box-shadow: 0 0 0 4px var(--accent-ring);
}
.input-wrap:focus-within .icon { color: var(--accent); }

.login-form .btn-primary { margin-top: 4px; }

.form-note {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-size: 12.5px;
  color: var(--text-3);
  text-align: center;
}
.form-note .icon { width: 13px; height: 13px; }

.divider {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 22px 0;
  font-size: 13px;
  color: var(--text-3);
}
.divider::before,
.divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line);
}

.btn-guest .icon { transition: transform .25s var(--ease); }
.btn-guest:hover .icon { transform: translateX(3px); }

.login-footer {
  padding: 24px 16px max(24px, env(safe-area-inset-bottom));
  text-align: center;
  font-size: 12.5px;
  color: var(--text-3);
}

/* Ponsel/tablet (login satu kolom): judul dan subjudul rata tengah */
@media (max-width: 959px) {
  .login-intro { justify-items: center; text-align: center; }
}

@media (max-width: 379px) {
  .login { padding-left: 12px; padding-right: 12px; }
  .login-card { padding: 22px 16px; }
  .login-card .btn { padding: 0 14px; }
}

@media (min-width: 640px) {
  .topbar { padding: 18px 24px 0; }
  .login { padding: 60px 24px 32px; }
  .login-card { padding: 34px 32px; }
}

@media (min-width: 960px) {
  .topbar { padding: 20px 40px 0; }
  .login {
    grid-template-columns: minmax(0, 1fr) 400px;
    gap: clamp(56px, 8vw, 120px);
    align-items: center;
    max-width: 1080px;
    padding: 48px 40px;
  }
  .login-intro { gap: 18px; }
}

@media (max-height: 520px) and (orientation: landscape) {
  .topbar { position: static; padding-top: 10px; }
  .login { padding-top: 24px; gap: 24px; }
  .login-title { font-size: 30px; }
}
@media (max-height: 520px) and (orientation: landscape) and (min-width: 640px) {
  .login {
    grid-template-columns: minmax(0, 1fr) minmax(320px, 380px);
    max-width: 900px;
    align-items: start;
  }
  .login-card { padding: 20px 24px; }
  .login-form { margin-top: 16px; gap: 12px; }
  .divider { margin: 14px 0; }
}

/* ==========================================================================
   PERCAKAPAN
   ========================================================================== */
.view-chat {
  display: flex;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

/* ---------- Sidebar (ponsel: drawer) ---------- */
.sidebar {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 40;
  display: flex;
  width: min(300px, 86vw);
  padding: 10px;
  padding-left: max(10px, env(safe-area-inset-left));
  padding-bottom: max(10px, env(safe-area-inset-bottom));
  transform: translateX(-105%);
  visibility: hidden;
  transition: transform var(--dur) var(--ease), visibility 0s linear var(--dur);
}
.sidebar.is-open {
  transform: none;
  visibility: visible;
  transition: transform var(--dur) var(--ease);
}

.sidebar-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 18px;
  min-width: 0;
  padding: 10px;
  border-radius: var(--r-xl);
  background: var(--glass-strong);
  overflow: hidden;
}

.sidebar-backdrop {
  position: fixed;
  inset: 0;
  z-index: 30;
  background: var(--overlay);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}

/* Baris atas selebar area dalam sidebar: tombol "Percakapan baru" mengisi sisa ruang,
   tombol bulat di ujung kanan. */
.sidebar-top { display: flex; align-items: center; gap: 8px; width: 100%; }

.side-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  min-height: var(--tap);
  padding: 0 14px;
  border-radius: var(--r);
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-2);
  font-size: 14.5px;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color .25s var(--ease), color .25s var(--ease), padding var(--dur) var(--ease);
}
.side-btn .icon { width: 19px; height: 19px; }
.side-btn:hover:not(:disabled) { background: var(--hover); color: var(--text); }

.new-chat {
  flex: 1 1 auto;
  min-width: 0;
  width: auto;
  padding: 0 18px;
  border-radius: var(--pill);
  border-color: var(--glass-border);
  background: var(--field);
  color: var(--text);
}
.new-chat:disabled { cursor: not-allowed; opacity: .6; }

/* Tombol bulat untuk meringkas/melebarkan sidebar */
.circle-btn {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--glass-border);
  background: var(--field);
  color: var(--text-2);
  transition: background-color .25s var(--ease), color .25s var(--ease);
}
.circle-btn:hover { background: var(--hover); color: var(--text); }
.circle-btn .icon { width: 18px; height: 18px; transition: transform var(--dur) var(--ease); }

.side-label { min-width: 0; overflow: hidden; text-overflow: ellipsis; transition: opacity .2s var(--ease); }

.history {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  transition: opacity .2s var(--ease);
}
.history-title {
  padding: 0 14px;
  margin-bottom: 8px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-3);
}
.history-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; }
.history-item {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 40px;
  padding: 0 14px;
  color: var(--text-3);
}
.history-item .icon { width: 16px; height: 16px; opacity: .6; }
.skeleton {
  display: block;
  flex: 1;
  height: 8px;
  border-radius: var(--pill);
  background: var(--hover);
}
.skeleton-short { flex: 0 0 55%; }
.history-empty {
  margin-top: 12px;
  padding: 0 14px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--text-3);
  white-space: normal;
}

.sidebar-foot {
  display: grid;
  gap: 4px;
  padding-top: 10px;
  border-top: 1px solid var(--line);
}
.guest-card {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 52px;
  padding: 0 8px;
  white-space: nowrap;
  transition: padding var(--dur) var(--ease);
}
.avatar {
  display: grid;
  place-items: center;
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: var(--pill);
  border: 1px solid var(--glass-border);
  background: var(--field);
  color: var(--text-2);
}
.avatar .icon { width: 17px; height: 17px; }
.guest-card strong { display: block; font-size: 14px; font-weight: 600; line-height: 1.3; }
.guest-card small { display: block; font-size: 12px; color: var(--text-3); }

/* ---------- Area chat ---------- */
.chat {
  position: relative;
  flex: 1;
  min-width: 0;
  --header-space: 76px;
  --composer-space: 112px;
}

/* Kontrol pojok (tanpa bilah header): menu drawer di ponsel, tema di kanan */
.chat-controls {
  position: absolute;
  top: 12px;
  left: max(12px, env(safe-area-inset-left));
  right: max(12px, env(safe-area-inset-right));
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  pointer-events: none;
}
.chat-controls > * { pointer-events: auto; }
.chat-actions { display: flex; align-items: center; gap: 8px; }
/* Tombol keluar: tinggi & bingkai sama dengan switcher tema di sebelahnya */
.logout-btn {
  border-radius: var(--pill);
  border: 1px solid var(--glass-border);
  background: var(--field);
  color: var(--text-2);
  text-decoration: none;
}
.logout-btn .icon { width: 18px; height: 18px; }
.mobile-menu { border-radius: var(--pill); color: var(--text); }

.chat-main {
  height: 100%;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}
.chat-main:focus { outline: none; }

.messages {
  display: flex;
  flex-direction: column;
  gap: 18px;
  width: 100%;
  max-width: var(--content-w);
  min-height: 100%;
  margin: 0 auto;
  padding: var(--header-space) 18px var(--composer-space);
}
.messages.is-empty { justify-content: center; }

.chat-prompt {
  display: grid;
  gap: 10px;
  text-align: center;
  text-wrap: balance;
}
.chat-prompt > span { display: block; transition: font-size var(--dur) var(--ease); }
.prompt-hello {
  font-size: clamp(30px, 6.4vw, 48px);
  line-height: 1.15;
  font-weight: 600;
  letter-spacing: -.025em;
}
.prompt-ask {
  margin-top: 4px;
  font-size: clamp(22px, 4.2vw, 34px);
  line-height: 1.25;
  font-weight: 600;
  letter-spacing: -.02em;
}
.messages:not(.is-empty) .chat-prompt { gap: 4px; margin-bottom: 10px; color: var(--text-2); }
.messages:not(.is-empty) .prompt-hello { font-size: clamp(20px, 3vw, 24px); }
.messages:not(.is-empty) .prompt-ask { font-size: clamp(16px, 2.4vw, 19px); }

.msg-user { display: flex; justify-content: flex-end; }
.msg-user .msg-body {
  max-width: min(85%, 560px);
  padding: 11px 18px;
  border-radius: 22px 22px 8px 22px;
  background: var(--accent-soft);
  border: 1px solid var(--glass-border);
}
.msg-user p { white-space: pre-wrap; overflow-wrap: anywhere; font-size: 15.5px; }

.msg-system {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 12px 16px;
  border-radius: var(--r);
  border: 1px solid var(--line);
  background: var(--field);
  font-size: 13.5px;
  color: var(--text-2);
}
.msg-system .icon { width: 16px; height: 16px; margin-top: 3px; color: var(--accent); }

/* ---------- Composer kapsul ---------- */
.composer-wrap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 10;
  padding: 0 12px max(14px, env(safe-area-inset-bottom));
  pointer-events: none;
}
.composer {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: var(--content-w);
  min-height: 60px;
  margin: 0 auto;
  padding: 7px 7px 7px 24px;
  border-radius: var(--pill);
  pointer-events: auto;
}
.composer:hover { background: var(--glass-hover); }
.composer:focus-within {
  border-color: var(--accent-edge);
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-hi), 0 0 0 4px var(--accent-ring);
}
.composer textarea {
  flex: 1;
  min-width: 0;
  max-height: 120px;
  padding: 10px 0;
  border: 0;
  background: transparent;
  font-size: 16px;
  line-height: 1.5;
  resize: none;
}
.composer textarea::placeholder { color: var(--text-3); }
.composer textarea:focus-visible { outline: none; }

.send-btn {
  display: grid;
  place-items: center;
  flex-shrink: 0;
  width: 46px;
  height: 46px;
  border: 0;
  border-radius: var(--pill);
  background: var(--accent-strong);
  color: var(--accent-ink);
  transition: background-color .25s var(--ease), color .25s var(--ease), transform .25s var(--ease);
}
.send-btn .icon { stroke-width: 2.2; }
.send-btn:hover:not(:disabled) { background: var(--accent); transform: scale(1.05); }
.send-btn:active:not(:disabled) { transform: scale(.95); }
.send-btn:disabled { cursor: not-allowed; background: var(--hover); color: var(--text-3); }

/* ---------- Tablet ke atas: header satu baris ---------- */
@media (min-width: 560px) {
  .chat { --composer-space: 120px; }
  .chat-controls { top: 16px; right: 16px; left: 16px; }
  .messages { padding-left: 28px; padding-right: 28px; }
  .composer-wrap { padding: 0 20px max(20px, env(safe-area-inset-bottom)); }
}

/* ---------- Desktop: sidebar terbuka atau diringkas menjadi rel ikon ---------- */
@media (min-width: 960px) {
  .sidebar-backdrop,
  .mobile-menu { display: none !important; }
  .chat-controls { justify-content: flex-end; }

  /*
   * Animasi buka/ringkas: hanya lebar yang berubah, tata letak isi tidak pernah
   * berganti mendadak. Tombol dipindah dengan left/top/width yang ikut
   * dianimasikan, teks memudar (opacity) dan tidak membungkus (nowrap), dan panel
   * memotong isi yang melewati batas (overflow: hidden).
   */
  .sidebar {
    --sb-dur: 300ms;
    --sb-ease: cubic-bezier(.4, 0, .2, 1);   /* ease-in-out */
    position: relative;
    inset: auto;
    z-index: 20;
    flex: 0 0 auto;
    width: var(--sb-expanded);
    padding: 12px 0 12px 12px;
    transform: none;
    visibility: visible;
    transition: width var(--sb-dur) var(--sb-ease);
  }
  .sidebar-panel { background: var(--glass); overflow: hidden; }

  /* Baris atas: posisi absolut agar bisa dianimasikan tanpa lompatan */
  .sidebar-top {
    position: relative;
    flex: 0 0 auto;
    height: var(--tap);
  }
  .sidebar-top .new-chat,
  .sidebar-top .sidebar-collapse {
    position: absolute;
    transition: left var(--sb-dur) var(--sb-ease), top var(--sb-dur) var(--sb-ease),
      width var(--sb-dur) var(--sb-ease), padding var(--sb-dur) var(--sb-ease),
      background-color .25s var(--ease), color .25s var(--ease);
  }
  /* Lebar area dalam sidebar terbuka = --sb-expanded - padding kiri sidebar (12) - padding panel (2x10) - border (2).
     Nilai tetap (bukan %) agar tombol bergerak seirama dengan tepi sidebar saat dianimasikan. */
  .sidebar { --sb-inner: calc(var(--sb-expanded) - 34px); }
  .sidebar-top .new-chat { left: 0; top: 0; width: calc(var(--sb-inner) - 48px); overflow: hidden; }
  .sidebar-top .sidebar-collapse { left: calc(var(--sb-inner) - 40px); top: 2px; }

  /* Teks: tidak membungkus, memudar halus. Saat melebar, teks muncul sedikit
     setelah ruang tersedia; saat meringkas, teks memudar lebih dulu. */
  .sidebar .side-label,
  .sidebar .history {
    white-space: nowrap;
    opacity: 1;
    transition: opacity 200ms ease 120ms, visibility 0s;
  }
  /* Lebar tetap agar paragraf tidak berubah susunan baris selama animasi */
  .sidebar .history,
  .sidebar .sidebar-foot { flex-shrink: 0; width: calc(var(--sb-expanded) - 34px); }
  .sidebar .history-empty { white-space: normal; }
  /* Avatar berada di posisi yang sama pada kedua keadaan */
  .sidebar .guest-card { padding: 0 5px; transition: none; }

  /* ----- Keadaan ringkas ----- */
  [data-sidebar="compact"] .sidebar { width: var(--sb-compact); }
  [data-sidebar="compact"] .sidebar-top .sidebar-collapse { left: 3px; top: 0; }
  [data-sidebar="compact"] .sidebar-top .new-chat { left: 1px; top: 50px; width: var(--tap); padding: 0 12.5px; }
  [data-sidebar="compact"] .sidebar-collapse .icon { transform: rotate(180deg); }
  [data-sidebar="compact"] .sidebar .side-label,
  [data-sidebar="compact"] .sidebar .history {
    opacity: 0;
    visibility: hidden;
    transition: opacity 120ms ease, visibility 0s linear 120ms;
  }
  [data-sidebar="compact"] .sidebar-foot { border-top-color: transparent; transition: border-color var(--sb-dur) var(--sb-ease); }

  .chat { --header-space: 80px; --composer-space: 128px; }
  .composer-wrap { padding-bottom: 24px; }
}

/* Landscape ponsel: ringkas */
@media (max-height: 520px) and (orientation: landscape) {
  .chat { --header-space: 64px; --composer-space: 92px; }
  .chat-controls { top: 8px; }
  .chat-prompt { gap: 4px; }
  .prompt-hello { font-size: 26px; }
  .prompt-ask { font-size: 20px; margin-top: 0; }
  .composer { min-height: 54px; }
  .composer-wrap { padding-bottom: max(10px, env(safe-area-inset-bottom)); }
  .send-btn { width: 40px; height: 40px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}