:root {
  --bg: #0f172a;
  --bg-soft: #111827;
  --card: #1e293b;
  --card-2: #243247;
  --text: #e5e7eb;
  --muted: #94a3b8;
  --line: rgba(148, 163, 184, 0.18);
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --shadow: 0 12px 32px rgba(15, 23, 42, 0.28);
}

body.light-theme {
  --bg: #f8fafc;
  --bg-soft: #eef2ff;
  --card: #ffffff;
  --card-2: #f8fafc;
  --text: #0f172a;
  --muted: #64748b;
  --line: rgba(15, 23, 42, 0.08);
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 100%);
  color: var(--text);
}

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

button,
input,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

.container,
.container-wide {
  width: min(1100px, calc(100% - 32px));
  margin: 0 auto;
}

.container {
  padding: 24px 0 40px;
}

.page-stack {
  display: grid;
  gap: 20px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.logo {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav a,
.nav button,
.nav span {
  color: var(--muted);
}

.nav a:hover,
.nav button:hover {
  color: var(--text);
}

.nav-inline-btn {
  border: none;
  background: transparent;
  padding: 0;
}

.theme-toggle {
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--text);
  width: 40px;
  height: 40px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
}

.card {
  background: color-mix(in srgb, var(--card) 92%, transparent);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
  padding: 22px;
}

.hero-page {
  display: grid;
  gap: 20px;
}

.hero-card {
  padding: 32px;
}

.hero-card h1,
.page-intro h1,
.auth-card h1,
.task-detail-card h1 {
  margin: 8px 0 12px;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #c7d2fe;
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.22);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 0.9rem;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 20px;
}

.notice-box {
  margin-top: 18px;
  padding: 14px 16px;
  border-radius: 14px;
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.24);
  color: #d1fae5;
}

.grid {
  display: grid;
  gap: 20px;
}

.grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.feature-card h3 {
  margin-top: 0;
  margin-bottom: 10px;
}

.btn {
  border: none;
  border-radius: 12px;
  padding: 10px 16px;
  font-weight: 600;
  transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-secondary {
  background: var(--card-2);
  color: var(--text);
  border: 1px solid var(--line);
}

.btn-block {
  width: 100%;
}

.auth-page {
  display: grid;
  place-items: center;
  min-height: calc(100vh - 120px);
}

.auth-card {
  width: min(460px, 100%);
}

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

.form-group {
  margin-top: 16px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
}

.form-group input,
.message-form-container textarea {
  width: 100%;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg-soft) 75%, var(--card));
  color: var(--text);
  border-radius: 12px;
  padding: 12px 14px;
  outline: none;
}

.form-group input:focus,
.message-form-container textarea:focus {
  border-color: rgba(99, 102, 241, 0.55);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.18);
}

.auth-tip {
  margin-top: 16px;
  color: var(--muted);
}

.auth-tip a {
  color: var(--primary);
}

.page-intro {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}

.user-badge {
  min-width: 180px;
  text-align: center;
  padding: 12px 14px;
  border-radius: 14px;
  background: color-mix(in srgb, var(--bg-soft) 78%, var(--card));
  border: 1px solid var(--line);
  color: var(--text);
}

.section-title-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  margin-bottom: 16px;
}

.section-title-row h2 {
  margin: 0;
}

.task-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.filter-btn {
  background: var(--card-2);
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 14px;
}

.filter-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: transparent;
}

.tasks {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 16px;
}

.task-card {
  width: 100%;
  text-align: left;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, color-mix(in srgb, var(--card) 96%, transparent) 0%, color-mix(in srgb, var(--card-2) 88%, transparent) 100%);
  border-radius: 18px;
  padding: 18px;
  color: var(--text);
  box-shadow: var(--shadow);
}

.task-card:hover {
  transform: translateY(-2px);
}

.task-card-head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: flex-start;
}

.task-title {
  font-size: 1rem;
  font-weight: 700;
}

.task-meta,
.message-top,
.task-desc-preview {
  color: var(--muted);
  font-size: 0.92rem;
}

.task-meta,
.task-desc-preview {
  margin-top: 12px;
}

.task-status,
.task-pin,
.meta-chip {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 5px 10px;
  font-size: 0.78rem;
  border: 1px solid transparent;
}

.task-status-building {
  background: rgba(245, 158, 11, 0.18);
  color: #fbbf24;
}

.task-status-completed {
  background: rgba(16, 185, 129, 0.18);
  color: #34d399;
}

.task-status-inactive {
  background: rgba(239, 68, 68, 0.18);
  color: #f87171;
}

.task-pin {
  margin-top: 12px;
  background: rgba(99, 102, 241, 0.16);
  color: #c7d2fe;
  border-color: rgba(99, 102, 241, 0.22);
}

.empty-state {
  margin-top: 12px;
  padding: 18px;
  border-radius: 14px;
  text-align: center;
  color: var(--muted);
  background: color-mix(in srgb, var(--bg-soft) 74%, var(--card));
  border: 1px dashed var(--line);
}

.hidden {
  display: none;
}

.messages-list {
  display: grid;
  gap: 12px;
}

.message-item {
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg-soft) 72%, var(--card));
  border-radius: 16px;
  padding: 14px;
}

.message-content {
  margin-top: 8px;
  white-space: pre-wrap;
  line-height: 1.6;
}

.message-form-container {
  margin-top: 18px;
}

.message-form-container label {
  display: block;
  margin-bottom: 10px;
  color: var(--muted);
}

.message-form-footer {
  margin-top: 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.task-detail-card {
  padding: 28px;
}

.task-detail-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 14px 0 18px;
}

.meta-chip {
  border-color: var(--line);
  background: color-mix(in srgb, var(--bg-soft) 76%, var(--card));
}

.task-detail-desc {
  margin: 0;
  line-height: 1.8;
  color: var(--text);
}

.task-detail-actions {
  margin-top: 24px;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  padding: 12px 16px;
  border-radius: 12px;
  background: rgba(15, 23, 42, 0.92);
  color: #fff;
  box-shadow: var(--shadow);
  z-index: 99;
}

@media (max-width: 900px) {
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .page-intro {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 640px) {
  .header-inner {
    align-items: flex-start;
    padding: 12px 0;
  }

  .hero-card,
  .card {
    padding: 18px;
  }

  .section-title-row,
  .message-form-footer {
    flex-direction: column;
    align-items: flex-start;
  }

  .tasks {
    grid-template-columns: 1fr;
  }
}