:root {
  --bg: #070a0d;
  --panel: rgba(12, 16, 19, 0.9);
  --panel-strong: rgba(5, 8, 10, 0.96);
  --line: rgba(201, 220, 224, 0.22);
  --line-strong: rgba(232, 238, 230, 0.56);
  --text: #eff4f1;
  --muted: #95a4a5;
  --cyan: #20c7df;
  --amber: #c99a56;
  --lime: #a7d742;
  --danger: #dd4f41;
  --font-ui: "Inter", "Segoe UI", "Microsoft YaHei", sans-serif;
  --font-condensed: "Arial Narrow", "Impact", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--bg);
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 74% 10%, rgba(32, 199, 223, 0.16), transparent 32rem),
    radial-gradient(circle at 12% 84%, rgba(201, 154, 86, 0.13), transparent 28rem),
    linear-gradient(120deg, #050708, #0d1114 58%, #050607);
  font-family: var(--font-ui);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.045) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.9), transparent 92%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    repeating-linear-gradient(
      to bottom,
      rgba(255, 255, 255, 0.032) 0,
      rgba(255, 255, 255, 0.032) 1px,
      transparent 1px,
      transparent 4px
    );
  opacity: 0.28;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
textarea {
  font: inherit;
}

.topic-shell {
  width: min(1280px, calc(100% - 44px));
  margin: 0 auto;
  padding: 26px 0 52px;
}

.topic-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  gap: 18px;
  min-height: 68px;
  margin-bottom: 42px;
  border: 1px solid var(--line);
  background: rgba(5, 8, 10, 0.82);
  backdrop-filter: blur(16px);
}

.topic-brand,
.topic-back {
  display: flex;
  align-items: center;
  padding: 0 18px;
}

.topic-brand {
  gap: 12px;
}

.topic-brand__mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line-strong);
  color: var(--cyan);
  font-weight: 900;
}

.topic-brand strong,
.topic-brand small {
  display: block;
}

.topic-brand strong {
  font-size: 0.94rem;
  letter-spacing: 0.08em;
}

.topic-brand small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 0.72rem;
}

.topic-back {
  border-left: 1px solid var(--line);
  color: #071015;
  background: var(--cyan);
  font-size: 0.82rem;
  font-weight: 900;
}

.topic-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.86fr) minmax(280px, 0.42fr);
  gap: 1px;
  margin-bottom: 34px;
  border: 1px solid var(--line);
  background: var(--line);
  overflow: hidden;
}

.topic-hero__copy,
.topic-hero__status {
  background: var(--panel-strong);
}

.topic-hero__copy {
  min-height: 360px;
  padding: clamp(28px, 5vw, 58px);
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--cyan);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.14em;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2 {
  font-family: var(--font-condensed);
  font-weight: 900;
  line-height: 0.9;
  letter-spacing: 0;
}

h1 {
  max-width: 760px;
  margin-bottom: 22px;
  font-size: clamp(4rem, 11vw, 10rem);
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(2rem, 5vw, 5rem);
}

h3 {
  margin-bottom: 10px;
}

.topic-hero__lead,
.board-note,
.post-card p,
.thread-form p {
  color: #c7d2d0;
  line-height: 1.8;
}

.topic-hero__status {
  display: grid;
  align-content: space-between;
  padding: clamp(22px, 4vw, 34px);
}

.status-list {
  display: grid;
  gap: 1px;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--line);
}

.status-list div {
  padding: 14px;
  background: #070a0d;
}

.status-list dt {
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
}

.status-list dd {
  margin: 0;
  font-weight: 900;
}

.topic-signal {
  margin-top: 24px;
  border-top: 1px solid var(--line);
  padding-top: 18px;
  color: var(--cyan);
  font-family: var(--font-condensed);
  font-size: clamp(2.2rem, 5vw, 4rem);
  line-height: 0.9;
}

.board-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.42fr);
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.thread-list,
.thread-form {
  background: rgba(6, 9, 11, 0.92);
}

.thread-list {
  min-height: 520px;
  padding: clamp(22px, 4vw, 36px);
}

.board-note {
  margin-bottom: 22px;
  padding: 14px 16px;
  border-left: 4px solid var(--cyan);
  background: rgba(32, 199, 223, 0.08);
}

.search-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(120px, 0.32fr) auto;
  gap: 10px;
  margin-bottom: 22px;
}

.search-form input {
  min-width: 0;
  min-height: 44px;
  border: 1px solid var(--line);
  background: rgba(3, 6, 8, 0.86);
  color: var(--text);
  padding: 0 12px;
}

.post-stack {
  display: grid;
  gap: 12px;
}

.post-card {
  position: relative;
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background:
    linear-gradient(90deg, rgba(32, 199, 223, 0.08), transparent 42%),
    rgba(11, 15, 18, 0.9);
}

.post-card::before {
  content: "";
  position: absolute;
  top: 18px;
  right: 18px;
  width: 44px;
  height: 2px;
  background: var(--cyan);
  opacity: 0.72;
}

.post-card header {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  align-items: baseline;
  margin-bottom: 12px;
  padding-right: 58px;
}

.post-card strong {
  font-size: 1rem;
}

.post-card time,
.post-card span {
  color: var(--muted);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
}

.post-card p {
  margin-bottom: 0;
}

.post-card__tags {
  margin-top: 14px;
  color: var(--cyan);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.06em;
}

.post-card .button {
  margin-top: 14px;
}

.post-card--reply {
  background:
    linear-gradient(90deg, rgba(201, 154, 86, 0.08), transparent 42%),
    rgba(11, 15, 18, 0.9);
}

.thread-form {
  padding: clamp(22px, 4vw, 34px);
}

.thread-form form {
  display: grid;
  gap: 16px;
  margin-bottom: 34px;
}

.thread-form h2:not(:first-child) {
  margin-top: 32px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
}

.reply-stack {
  display: grid;
  gap: 10px;
  margin-bottom: 18px;
}

.field {
  display: grid;
  gap: 8px;
}

.field span {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.12em;
}

.field input,
.field textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 0;
  background: rgba(3, 6, 8, 0.86);
  color: var(--text);
  outline: 0;
}

.field input {
  min-height: 44px;
  padding: 0 12px;
}

.field textarea {
  min-height: 160px;
  resize: vertical;
  padding: 12px;
  line-height: 1.7;
}

.field input:focus,
.field textarea:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 1px rgba(32, 199, 223, 0.3);
}

.form-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.button {
  min-height: 44px;
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  padding: 0 16px;
  font-weight: 900;
  cursor: pointer;
}

.button:hover,
.button:focus-visible {
  border-color: var(--cyan);
}

.button--primary {
  border-color: transparent;
  background: var(--cyan);
  color: #071015;
}

.button--ghost {
  color: var(--muted);
}

.form-status {
  min-height: 1.4em;
  margin: 0;
  color: var(--cyan);
  font-size: 0.82rem;
}

.topic-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 24px 0 0;
  color: var(--muted);
  font-size: 0.82rem;
}

@media (max-width: 980px) {
  .topic-header {
    position: static;
    flex-direction: column;
  }

  .topic-back {
    min-height: 48px;
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .topic-hero,
  .board-grid {
    grid-template-columns: 1fr;
  }

  .search-form {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .topic-shell {
    width: min(100% - 28px, 1280px);
    padding-top: 14px;
  }

  .topic-brand {
    align-items: flex-start;
    padding: 14px;
  }

  .topic-hero__copy {
    min-height: auto;
  }

  h1 {
    font-size: clamp(3.4rem, 18vw, 5.8rem);
  }

  .topic-footer {
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}