@layer reset, tokens, layout, components;

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

  html {
    font-size: 100%;
    text-size-adjust: none;
    background: var(--paper);
  }

  body {
    margin: 0;
    min-block-size: 100dvh;
    color: var(--text);
    font-family: var(--font-body);
    font-size: var(--step-0);
    line-height: 1.5;
    background: var(--paper);
  }

  img, svg { display: block; max-inline-size: 100%; }
  button, input, textarea { font: inherit; color: inherit; }
  [hidden] { display: none !important; }

  :focus-visible {
    outline: 0.12rem solid var(--accent);
    outline-offset: 0.15rem;
  }
}

@layer tokens {
  :root {
    color-scheme: dark;
    --paper: #0b0614;
    --ink: #1a0b2e;
    --text: #f7f2ff;
    --muted: #b8a9d4;
    --accent: #f0c14a;
    --accent-hot: #ff5c8a;
    --glow: #7c5cff;
    --panel: color-mix(in oklab, #2a1548 78%, transparent);
    --font-body: "Segoe UI", "Helvetica Neue", system-ui, sans-serif;
    --font-display: "Iowan Old Style", Palatino, "Palatino Linotype", Georgia, serif;
    --step-0: 1rem;
    --step-1: 1.15rem;
    --step-2: clamp(1.5rem, 1.1rem + 1.4vw, 2.2rem);
    --step-3: clamp(2rem, 1.4rem + 2.2vw, 3.2rem);
    --space-s: 0.7rem;
    --space-m: 1rem;
    --space-l: 1.5rem;
    --space-xl: 2.5rem;
    --radius: 0.85rem;
    --measure: 40rem;
    --touch: 2.75rem;
  }
}

@layer layout {
  .shell {
    display: flex;
    flex-direction: column;
    gap: var(--space-l);
    max-inline-size: var(--measure);
    margin-inline: auto;
    padding: var(--space-l);
    min-block-size: 100dvh;
  }

  header {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
  }

  .chat-head {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-s);
  }

  .brand {
    font-family: var(--font-display);
    font-size: var(--step-3);
    line-height: 1.2;
    letter-spacing: 0.01em;
    color: var(--accent);
    text-wrap: balance;
    margin: 0;
  }

  .chat-head .brand {
    font-size: var(--step-2);
    line-height: 1.2;
  }

.generated-at {
  color: var(--muted);
  font-size: var(--step-0);
  margin: 0 0 var(--space-m);
}

  .lede {
    color: var(--muted);
    font-size: var(--step-1);
    max-inline-size: 32rem;
  }

  .chat {
    display: flex;
    flex-direction: column;
    gap: var(--space-m);
    flex: 1;
  }

  .chat-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
  }

  .chat-row {
    text-decoration: none;
    color: inherit;
  }

  .chat-row-title {
    font-weight: 700;
  }

  .chat-row-meta {
    color: var(--muted);
    font-size: var(--step-0);
  }

  .reading-row-main {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-s);
    flex-wrap: wrap;
  }

  .reading-info {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
  }

  .reading-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
  }

  .section-title {
    font-size: var(--step-1);
    font-weight: 700;
    margin-block-start: var(--space-m);
    margin-block-end: var(--space-s);
    color: var(--accent);
  }

  .bubble {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
    padding: var(--space-m) var(--space-l);
    border-radius: var(--radius);
    background: var(--panel);
    border: 0.06rem solid color-mix(in oklab, var(--glow) 35%, transparent);
    box-shadow: 0 0 2rem color-mix(in oklab, var(--glow) 18%, transparent);
  }

  .bubble-out {
    align-self: flex-start;
    max-inline-size: 95%;
  }

  .bubble-out:has(.picker), .bubble-out:has(.date-picker-control) {
    inline-size: min(24rem, 95%);
  }

  .bubble-in {
    align-self: flex-end;
    max-inline-size: 85%;
    background: color-mix(in oklab, var(--accent-hot) 22%, var(--panel));
  }

  .chat-body {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
  }

  .chat-body p {
    margin: 0;
  }

  .chat-body h1, .chat-body h2, .chat-body h3, .chat-body h4 {
    font-family: var(--font-display);
    color: var(--accent);
    line-height: 1.25;
    margin: 0;
  }

  .chat-body h1 { font-size: var(--step-2); }
  .chat-body h2 { font-size: var(--step-1); }
  .chat-body h3 { font-size: var(--step-0); color: color-mix(in oklab, var(--accent) 88%, var(--text)); }
  .chat-body h4 { font-size: var(--step-0); }

  .chat-body ul, .chat-body ol {
    margin: 0;
    padding-inline-start: 1.35rem;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
  }

  .chat-body li {
    margin: 0;
    line-height: 1.45;
  }

  .chat-body strong {
    color: var(--text);
    font-weight: 700;
  }

  .chat-body em {
    color: var(--accent);
    font-style: normal;
    font-weight: 600;
  }

  .chat-body code {
    font-family: monospace;
    font-size: 0.9em;
    background: color-mix(in oklab, var(--ink) 80%, transparent);
    padding: 0.15rem 0.35rem;
    border-radius: 0.35rem;
  }

  .chat-body blockquote {
    margin: 0;
    padding-inline-start: var(--space-m);
    border-inline-start: 0.2rem solid var(--accent);
    color: var(--muted);
  }

  .actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-s);
  }

  .actions form.button_to {
    display: inline-flex;
    margin: 0;
  }

  .user-name {
    display: inline-flex;
    align-items: center;
    color: var(--muted);
    font-size: var(--step-0);
    font-weight: 600;
    padding-inline: 0.25rem;
    max-inline-size: 14rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .composer {
    display: flex;
    gap: var(--space-s);
    margin-block-start: auto;
  }

  .composer input {
    flex: 1;
    min-block-size: var(--touch);
    border-radius: var(--radius);
    border: 0.06rem solid color-mix(in oklab, var(--accent) 40%, transparent);
    background: color-mix(in oklab, var(--ink) 70%, transparent);
    padding-inline: var(--space-m);
  }

  .composer input:disabled {
    opacity: 0.55;
    cursor: not-allowed;
  }

  .picker form.button_to {
    display: flex;
    flex: 1 0 3.4rem;
    max-inline-size: 6rem;
  }

  .picker form.button_to .btn {
    inline-size: 100%;
    padding-inline: 0.35rem;
    border-radius: var(--radius);
    font-size: 0.95rem;
  }

  .date-picker-control {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
    inline-size: 100%;
  }

  .picker-cols-5 {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: var(--space-xs, 0.35rem);
    inline-size: 100%;
  }

  .picker-cols-5 .btn {
    inline-size: 100%;
    padding-inline: 0.2rem;
    font-size: 0.88rem;
  }

  .picker-cols-2 {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-s, 0.5rem);
    inline-size: 100%;
  }

  .picker-cols-2 .btn {
    inline-size: 100%;
    padding-inline: 0.4rem;
    font-size: 0.88rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .picker-nav {
    grid-column: 1 / -1;
  }

  .picker-decade-nav {
    display: flex;
    justify-content: space-between;
    gap: var(--space-s);
    grid-column: 1 / -1;
  }

  .picker-decade-nav .btn {
    flex: 1;
  }

  .report-wait {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
  }

  .report-wait p {
    margin: 0;
  }

  .report-wait-bar {
    block-size: 0.5rem;
    border-radius: 999px;
    background: color-mix(in oklab, var(--ink) 45%, transparent);
    overflow: hidden;
  }

  .report-wait-fill {
    display: block;
    block-size: 100%;
    inline-size: var(--progress, 6%);
    border-radius: inherit;
    background: linear-gradient(90deg, var(--accent-hot), var(--glow), var(--accent));
  }

  .streaming-answer {
    position: relative;
    min-block-size: 1.5rem;
  }

  .typing-cursor {
    display: inline-block;
    inline-size: 0.45rem;
    block-size: 1rem;
    margin-inline-start: 0.25rem;
    vertical-align: -0.15rem;
    background: var(--accent);
    border-radius: 1px;
    animation: cursor-blink 0.8s infinite;
  }

  @keyframes cursor-blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
  }
}

@layer components {
  .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    vertical-align: middle;
    min-block-size: var(--touch);
    padding-inline: var(--space-m);
    border: 0.08rem solid color-mix(in oklab, white 22%, transparent);
    border-radius: 999px;
    background: linear-gradient(180deg, color-mix(in oklab, white 18%, var(--accent-hot)), var(--glow));
    color: white;
    font-weight: 650;
    text-decoration: none;
    cursor: pointer;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    box-shadow:
      inset 0 0.1rem 0 color-mix(in oklab, white 28%, transparent),
      0 0.28rem 0 color-mix(in oklab, black 35%, transparent),
      0 0.4rem 1.2rem color-mix(in oklab, var(--accent-hot) 35%, transparent);
    transition: transform 80ms ease, box-shadow 80ms ease, filter 80ms ease, background 80ms ease;
  }

  .btn:hover {
    filter: brightness(1.08);
  }

  .btn:active {
    transform: translateY(0.14rem) scale(0.97);
    filter: brightness(0.88);
    box-shadow:
      inset 0 0.22rem 0.5rem color-mix(in oklab, black 48%, transparent),
      0 0.06rem 0 color-mix(in oklab, black 25%, transparent);
  }

  .btn:disabled,
  button:disabled,
  input[type="submit"]:disabled {
    opacity: 0.45;
    cursor: not-allowed;
    pointer-events: none;
    box-shadow: none;
    filter: grayscale(0.5);
  }

  .btn-ghost {
    background: color-mix(in oklab, var(--ink) 55%, transparent);
    border: 0.08rem solid color-mix(in oklab, var(--accent) 55%, transparent);
    color: var(--accent);
    box-shadow:
      inset 0 0.08rem 0 color-mix(in oklab, white 14%, transparent),
      0 0.22rem 0 color-mix(in oklab, black 28%, transparent);
  }

  .btn-ghost:hover {
    background: color-mix(in oklab, var(--accent) 16%, var(--ink));
  }

  .btn-ghost:active {
    background: color-mix(in oklab, var(--accent) 22%, var(--ink));
  }

  .report {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
  }

  .report h1, .report h2, .report h3 {
    font-family: var(--font-display);
    color: var(--accent);
    line-height: 1.15;
    margin: 0;
    margin-block-start: var(--space-l);
  }

  .report > :first-child {
    margin-block-start: 0;
  }

  .report h1 { font-size: var(--step-2); }
  .report h2 { font-size: var(--step-1); }
  .report .report-chapter { text-transform: uppercase; }
  .report h3 { font-size: var(--step-0); color: color-mix(in oklab, var(--accent) 80%, var(--text)); }

  .report p {
    margin: 0;
  }

  .report strong {
    color: var(--text);
    font-weight: 700;
  }

  .report em {
    color: var(--accent);
    font-style: normal;
    font-weight: 600;
  }

  .report-calc {
    padding: var(--space-s) var(--space-m);
    border-radius: var(--radius);
    background: color-mix(in oklab, var(--accent) 18%, var(--paper));
  }

  .report-math {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
    padding: var(--space-m);
    border-radius: var(--radius);
    background: color-mix(in oklab, var(--accent) 14%, var(--paper));
  }

  .report-math-caption {
    color: var(--accent);
    font-weight: 700;
  }

  .report-math-align {
    align-self: start;
    margin: 0;
    border-collapse: collapse;
    font-variant-numeric: tabular-nums;
  }

  .report-math-align td {
    padding: 0.12rem 0.35rem;
    vertical-align: baseline;
  }

  .report-math-lhs {
    text-align: right;
    white-space: nowrap;
  }

  .report-math-eq {
    text-align: center;
    color: var(--muted);
  }

  .report-math-rhs {
    text-align: left;
  }

  .report-math-align tr:last-child td {
    color: var(--accent);
    font-weight: 700;
    padding-block-start: 0.35rem;
  }

  .report-fact {
    color: color-mix(in oklab, var(--accent) 55%, var(--text));
  }

  .report-sheet {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
    padding: var(--space-s);
    border-radius: var(--radius);
    background: color-mix(in oklab, var(--accent) 12%, var(--paper));
  }

  .report-sheet-caption {
    color: var(--accent);
    font-weight: 700;
  }

  .report-sheet-grid {
    width: 100%;
    border-collapse: collapse;
    table-layout: fixed;
    font-variant-numeric: tabular-nums;
  }

  .report-sheet-grid th, .report-sheet-grid td {
    border: 0.06rem solid color-mix(in oklab, var(--accent) 40%, transparent);
    text-align: center;
    padding: 0.35rem 0.15rem;
  }

  .report-sheet-grid th {
    color: var(--accent);
    font-size: 0.85rem;
  }

  .report-sheet-grid td {
    font-weight: 700;
  }

  .report-toolbox {
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
    padding: var(--space-m);
    border-radius: var(--radius);
    border: 0.08rem solid color-mix(in oklab, var(--accent) 55%, transparent);
    background: color-mix(in oklab, var(--accent) 10%, var(--paper));
  }

  .report-toolbox-title {
    color: var(--accent);
    font-weight: 700;
  }

  .report-toolbox-price {
    text-align: center;
    color: var(--accent);
    font-weight: 700;
  }

  .report-toolbox-meta {
    text-align: center;
    color: var(--muted);
    font-size: 0.9rem;
  }

  .report-contacts {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    margin-block-start: var(--space-l);
    padding: var(--space-m);
    border-radius: var(--radius);
    border: 0.08rem solid color-mix(in oklab, var(--accent) 55%, transparent);
    background: color-mix(in oklab, var(--accent) 8%, var(--paper));
    text-align: center;
  }

  .report-contacts p { margin: 0; }

  .report-contacts-tg {
    color: var(--accent);
    font-weight: 700;
  }

  .report-contacts-title {
    font-weight: 700;
  }

  .report-contacts-donate {
    color: var(--accent);
  }

  .report ul {
    margin: 0;
    padding-inline-start: 1.2rem;
    display: flex;
    flex-direction: column;
    gap: var(--space-s);
  }

  .report li::marker {
    color: var(--accent-hot);
  }

  .flash {
    padding: var(--space-s) var(--space-m);
    border-radius: var(--radius);
    font-size: var(--step-0);
  }

  .flash-notice {
    background: color-mix(in oklab, var(--glow) 25%, var(--panel));
    border: 0.06rem solid color-mix(in oklab, var(--glow) 50%, transparent);
    color: var(--text);
  }

  .flash-alert {
    background: color-mix(in oklab, var(--accent-hot) 20%, var(--panel));
    border: 0.06rem solid color-mix(in oklab, var(--accent-hot) 50%, transparent);
    color: var(--text);
  }

  .login-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-m);
    padding: var(--space-l);
    border-radius: var(--radius);
    background: var(--panel);
    border: 0.06rem solid color-mix(in oklab, var(--glow) 35%, transparent);
    box-shadow: 0 0 2rem color-mix(in oklab, var(--glow) 18%, transparent);
    inline-size: 100%;
    max-inline-size: 24rem;
  }

  .login-divider {
    display: flex;
    align-items: center;
    inline-size: 100%;
    color: var(--muted);
    font-size: var(--step-0);
  }

  .login-divider::before,
  .login-divider::after {
    content: "";
    flex: 1;
    border-bottom: 0.06rem solid color-mix(in oklab, var(--glow) 25%, transparent);
  }

  .login-divider span {
    padding-inline: var(--space-s);
  }

  .telegram-widget-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    min-block-size: 2.75rem;
    inline-size: 100%;
  }

  .widget-hint {
    color: var(--muted);
    font-size: var(--step-0);
    text-align: center;
    margin: 0;
  }


  /* OpenID login button (Telegram Login redirect flow). */
  .oidc-login-button {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    min-block-size: 2.75rem;
    padding: 0 var(--space-m);
    border-radius: 0.75rem;
    background: #229ed9;
    color: #fff;
    font-size: var(--step-0);
    font-weight: 600;
    text-decoration: none;
  }

  .oidc-login-button:hover {
    filter: brightness(1.08);
  }

  /* Floating back-to-top control; shown only after scrolling past roughly the first screenful. */
  .to-top {
    position: fixed;
    z-index: 10;
    inset-block-end: calc(var(--space-m) + env(safe-area-inset-bottom, 0px));
    inset-inline-end: var(--space-m);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    inline-size: var(--touch);
    block-size: var(--touch);
    padding: 0;
    border: 0.08rem solid color-mix(in oklab, var(--accent) 45%, transparent);
    border-radius: 50%;
    background: color-mix(in oklab, var(--ink) 80%, transparent);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: var(--accent);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(var(--space-s));
    transition: opacity 160ms ease, transform 160ms ease, visibility 160ms;
    box-shadow: 0 0.25rem 0.8rem color-mix(in oklab, black 60%, transparent);
    user-select: none;
    -webkit-tap-highlight-color: transparent;
  }

  .to-top .glyph {
    inline-size: 1.25em;
    block-size: 1.25em;
  }

  .to-top.is-on {
    opacity: 0.75;
    visibility: visible;
    transform: translateY(0);
  }

  .to-top:hover,
  .to-top:focus-visible {
    opacity: 1;
    background: color-mix(in oklab, var(--accent) 18%, var(--ink));
    box-shadow: 0 0.35rem 1rem color-mix(in oklab, var(--glow) 40%, transparent);
  }

  @media (prefers-reduced-motion: reduce) {
    .to-top {
      transition: none;
      transform: none;
    }
  }
}