/* =========================================================
   BeatMail — BeatCraft visual system
   sky blue · bright yellow · coral pink · grass green
   deep navy shadows · pure white highlights
   chunky game art · centered canvas · on-canvas HUD
   ========================================================= */

:root {
  --sky: #4FC3F7;
  --sky-deep: #29B6F6;
  --yellow: #FFEB3B;
  --yellow-hot: #FFD600;
  --coral: #FF6F91;
  --coral-hot: #FF4081;
  --green: #69F0AE;
  --green-hot: #00E676;
  --navy: #1A237E;
  --navy-ink: #0D1B4C;
  --white: #FFFFFF;
  --cream: #FFF8E7;
  --ink: #1A237E;
  --muted: #5C6BC0;
  --danger: #FF5252;
  --good: #00C853;

  --shadow: 0 6px 0 var(--navy);
  --shadow-sm: 0 3px 0 var(--navy);
  --shadow-lg: 0 10px 0 var(--navy);
  --radius: 18px;
  --radius-sm: 12px;
  --radius-pill: 999px;

  --font-display: "Fredoka", "Nunito", system-ui, sans-serif;
  --font-body: "Nunito", system-ui, sans-serif;

  --bg1: #81D4FA;
  --bg2: #B2EBF2;
}

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

html, body {
  margin: 0;
  min-height: 100%;
  min-height: 100dvh;
  font-family: var(--font-body);
  color: var(--ink);
  background: linear-gradient(160deg, var(--bg1) 0%, var(--bg2) 55%, #E1F5FE 100%);
  background-attachment: fixed;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
}

body.reduced-motion *,
body.reduced-motion *::before,
body.reduced-motion *::after {
  animation-duration: 0.01ms !important;
  animation-iteration-count: 1 !important;
  transition-duration: 0.01ms !important;
}

/* floating orbs */
.bg-orbs {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(2px);
  opacity: 0.55;
  animation: float 12s ease-in-out infinite;
}
.orb-a {
  width: 180px; height: 180px;
  background: var(--yellow);
  top: 8%; left: 6%;
  box-shadow: 0 0 0 8px rgba(255, 235, 59, 0.25);
}
.orb-b {
  width: 120px; height: 120px;
  background: var(--coral);
  top: 60%; right: 8%;
  animation-delay: -4s;
  box-shadow: 0 0 0 8px rgba(255, 111, 145, 0.2);
}
.orb-c {
  width: 90px; height: 90px;
  background: var(--green);
  bottom: 12%; left: 30%;
  animation-delay: -7s;
  box-shadow: 0 0 0 6px rgba(105, 240, 174, 0.25);
}
@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-18px) scale(1.05); }
}

/* app shell — PC 与顶栏同宽 */
.app {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 20px 24px 56px;
  padding-left: max(24px, env(safe-area-inset-left, 0px));
  padding-right: max(24px, env(safe-area-inset-right, 0px));
}

/* ── HUD ─────────────────────────────────────────── */
.hud {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--white);
  border: 3px solid var(--navy);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 10px 14px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 160px;
}
.brand-mark {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  font-size: 26px;
  background: var(--yellow);
  border: 3px solid var(--navy);
  border-radius: 14px;
  box-shadow: var(--shadow-sm);
}
.brand-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.45rem;
  letter-spacing: 0.02em;
  line-height: 1.1;
  color: var(--navy);
}
.brand-tag {
  margin: 0;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hud-metrics {
  display: flex;
  gap: 10px;
  flex: 1;
  justify-content: center;
  flex-wrap: wrap;
}
.metric {
  background: var(--cream);
  border: 2px solid var(--navy);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  min-width: 72px;
  text-align: center;
  box-shadow: var(--shadow-sm);
}
.metric-label {
  display: block;
  font-size: 0.65rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  color: var(--muted);
}
.metric-value {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--navy);
  line-height: 1.1;
}
.metric-value.sm {
  font-size: 0.95rem;
}
.metric-status {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 100px;
  justify-content: center;
}
.status-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--green-hot);
  border: 2px solid var(--navy);
  box-shadow: 0 0 0 3px rgba(0, 230, 118, 0.25);
  animation: pulse-dot 1.6s ease-in-out infinite;
}
.status-dot.warn { background: var(--yellow-hot); box-shadow: 0 0 0 3px rgba(255, 214, 0, 0.3); }
.status-dot.bad  { background: var(--danger); box-shadow: 0 0 0 3px rgba(255, 82, 82, 0.3); animation: none; }
@keyframes pulse-dot {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.15); }
}

.hud-toggles {
  display: flex;
  gap: 8px;
}

.icon-btn {
  width: 42px;
  height: 42px;
  border: 3px solid var(--navy);
  border-radius: 12px;
  background: var(--cream);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  font-size: 1.1rem;
  transition: transform 0.08s ease, box-shadow 0.08s ease;
}
.icon-btn:hover { transform: translateY(-1px); }
.icon-btn:active {
  transform: translateY(2px);
  box-shadow: 0 1px 0 var(--navy);
}
.icon-btn[aria-pressed="false"] {
  opacity: 0.55;
  filter: grayscale(0.4);
}

/* ── Screens ─────────────────────────────────────── */
.screen { display: none; }
.screen.is-active { display: block; animation: pop-in 0.35s cubic-bezier(.2,1.2,.4,1); }
@keyframes pop-in {
  from { opacity: 0; transform: scale(0.96) translateY(8px); }
  to   { opacity: 1; transform: none; }
}

/* Start / Hero — 与顶栏同宽，不再窄成手机卡片 */
.screen-start {
  display: none;
}
.screen-start.is-active {
  display: block;
  width: 100%;
  animation: pop-in 0.35s cubic-bezier(.2,1.2,.4,1);
}

.hero-card {
  width: 100%;
  max-width: none;
  background: var(--white);
  border: 4px solid var(--navy);
  border-radius: 28px;
  box-shadow: var(--shadow-lg);
  padding: 32px 36px 28px;
  text-align: left;
  position: relative;
  overflow: hidden;
}
.hero-card::before {
  content: "";
  position: absolute;
  top: -40px; right: -40px;
  width: 140px; height: 140px;
  background: var(--coral);
  border-radius: 50%;
  opacity: 0.22;
  pointer-events: none;
}

/* PC：左右两栏 — 介绍 | 表单 */
.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 32px;
  align-items: center;
  position: relative;
  z-index: 1;
}
.hero-left {
  text-align: left;
}
.hero-right {
  text-align: left;
}

.hero-badge {
  display: inline-block;
  background: var(--coral);
  color: var(--white);
  font-weight: 800;
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  border: 2px solid var(--navy);
  margin-bottom: 10px;
}
.hero-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--navy);
  letter-spacing: 0.02em;
  text-shadow: 3px 3px 0 var(--yellow);
}
.hero-tagline {
  margin: 0 0 18px;
  color: var(--muted);
  font-weight: 600;
  line-height: 1.5;
  font-size: 1.05rem;
}

.rules {
  list-style: none;
  margin: 0;
  padding: 0;
  text-align: left;
}
.rules li {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--cream);
  border: 2px solid var(--navy);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  margin-bottom: 8px;
  font-weight: 700;
  font-size: 0.95rem;
  box-shadow: var(--shadow-sm);
}

.start-form {
  display: grid;
  gap: 12px;
  margin-bottom: 16px;
  text-align: left;
}

.rule-ico {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  border: 2px solid var(--navy);
  font-weight: 800;
  font-size: 0.85rem;
  flex-shrink: 0;
}
.rule-ico.good { background: var(--green); color: var(--navy); }

.field-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 4px;
}
.field-label em {
  font-style: normal;
  font-weight: 600;
  opacity: 0.7;
  text-transform: none;
  letter-spacing: 0;
}
.field-input {
  width: 100%;
  border: 3px solid var(--navy);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 700;
  color: var(--navy);
  background: var(--cream);
  outline: none;
  box-shadow: inset 0 2px 0 rgba(26, 35, 126, 0.06);
  transition: background 0.15s, box-shadow 0.15s;
}
.field-input:focus {
  background: var(--white);
  box-shadow: 0 0 0 3px rgba(79, 195, 247, 0.45);
}
.field-select {
  cursor: pointer;
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--navy) 50%),
                    linear-gradient(135deg, var(--navy) 50%, transparent 50%);
  background-position: calc(100% - 18px) calc(50% - 3px), calc(100% - 12px) calc(50% - 3px);
  background-size: 6px 6px, 6px 6px;
  background-repeat: no-repeat;
  padding-right: 36px;
}

/* Buttons */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 3px solid var(--navy);
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  cursor: pointer;
  padding: 12px 22px;
  box-shadow: var(--shadow);
  transition: transform 0.08s ease, box-shadow 0.08s ease;
  user-select: none;
  color: var(--navy);
  background: var(--white);
  overflow: hidden;
}
.btn:hover { transform: translateY(-2px); }
.btn:active {
  transform: translateY(3px);
  box-shadow: 0 2px 0 var(--navy);
}
.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
}
.btn-play {
  width: 100%;
  background: linear-gradient(180deg, var(--yellow) 0%, var(--yellow-hot) 100%);
  font-size: 1.2rem;
  padding: 16px 24px;
  letter-spacing: 0.04em;
}
.btn-play .btn-shine {
  position: absolute;
  inset: 0;
  background: linear-gradient(105deg, transparent 40%, rgba(255,255,255,0.55) 50%, transparent 60%);
  transform: translateX(-120%);
  animation: shine 2.8s ease-in-out infinite;
}
@keyframes shine {
  0%, 60%, 100% { transform: translateX(-120%); }
  75% { transform: translateX(120%); }
}
.btn-secondary {
  background: var(--sky);
  color: var(--navy-ink);
  box-shadow: var(--shadow-sm);
  padding: 10px 14px;
  font-size: 0.9rem;
}
.btn-ghost {
  background: var(--white);
  box-shadow: var(--shadow-sm);
  padding: 10px 14px;
  font-size: 0.9rem;
}

.hint {
  margin: 14px 0 0;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--muted);
  text-align: center;
}

/* PC 右侧表单区视觉区分 */
.hero-right {
  background: var(--cream);
  border: 3px solid var(--navy);
  border-radius: 20px;
  padding: 22px 20px;
  box-shadow: var(--shadow-sm);
}
.hero-resources {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  align-items: stretch;
}
.resource-card {
  background: linear-gradient(180deg, #FFFFFF 0%, #FFF8E7 100%);
  border: 3px solid var(--navy);
  border-radius: 18px;
  box-shadow: var(--shadow-sm);
  padding: 12px;
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  grid-template-areas:
    "icon header"
    "button button";
  gap: 10px;
  align-items: center;
  overflow: hidden;
}
.resource-api {
  background: linear-gradient(180deg, #E1F5FE 0%, #FFFFFF 100%);
}
.resource-source {
  background: linear-gradient(180deg, #FFFFFF 0%, #FFF8E7 100%);
}
.resource-icon {
  grid-area: icon;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  background: var(--yellow);
  border: 3px solid var(--navy);
  border-radius: 14px;
  box-shadow: 0 3px 0 var(--navy);
  font-size: 1.25rem;
}
.resource-source .resource-icon {
  background: var(--green);
}
.resource-header {
  grid-area: header;
  min-width: 0;
  display: grid;
  gap: 2px;
}
.resource-kicker {
  width: fit-content;
  padding: 2px 8px;
  border: 2px solid var(--navy);
  border-radius: var(--radius-pill);
  background: var(--coral);
  color: var(--white);
  font-size: 0.62rem;
  font-weight: 900;
  letter-spacing: 0.12em;
}
.resource-body {
  padding: 12px 14px 14px;
}
.resource-title {
  font-family: var(--font-display);
  font-size: 0.98rem;
  line-height: 1.1;
  font-weight: 800;
  color: var(--navy);
}
.resource-subtitle {
  font-size: 0.72rem;
  line-height: 1.2;
  font-weight: 800;
  color: var(--muted);
}
.resource-text {
  margin: 0;
  font-size: 0.82rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--muted);
}
.api-endpoints {
  margin: 10px 0 0;
  padding-left: 18px;
  font-size: 0.82rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--navy);
}
.api-endpoints code,
.resource-text code,
.resource-note code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.92em;
}
.api-snippet {
  margin-top: 12px;
}
.api-snippet-title {
  margin-bottom: 6px;
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--coral-hot);
}
.api-code {
  margin: 0;
  padding: 12px;
  background: var(--navy-ink);
  color: var(--cream);
  border: 2px solid var(--navy);
  border-radius: 14px;
  overflow-x: auto;
  font-size: 0.74rem;
  line-height: 1.45;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}
.api-code code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}
.codebox {
  margin: 0;
  max-width: 100%;
  background: var(--navy-ink);
  border: 3px solid var(--navy);
  border-radius: 16px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}
.codebox-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 10px;
  background: linear-gradient(180deg, var(--yellow), var(--yellow-hot));
  border-bottom: 3px solid var(--navy);
  color: var(--navy);
}
.codebox-title {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.codecopy-btn {
  border: 2px solid var(--navy);
  border-radius: var(--radius-pill);
  background: var(--white);
  color: var(--navy);
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 900;
  padding: 4px 10px;
  cursor: pointer;
  box-shadow: 0 2px 0 var(--navy);
}
.codecopy-btn:active {
  transform: translateY(2px);
  box-shadow: none;
}
.codebox-body {
  margin: 0;
  max-height: 520px;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
  padding: 0;
  counter-reset: code-line;
  list-style: none;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.78rem;
  line-height: 1.55;
  color: var(--cream);
  background-image: linear-gradient(rgba(255,255,255,0.035) 50%, transparent 50%);
  background-size: 100% 3.1em;
}
.codebox-body li {
  display: grid;
  grid-template-columns: 3.2em max-content;
  gap: 12px;
  min-width: max-content;
  min-height: 1.55em;
  padding-right: 14px;
  counter-increment: code-line;
}
.codebox-body li::before {
  content: counter(code-line);
  padding: 0 8px;
  text-align: right;
  color: rgba(255, 248, 231, 0.5);
  background: rgba(255, 255, 255, 0.08);
  border-right: 1px solid rgba(255, 248, 231, 0.16);
  user-select: none;
}
.codebox-body code {
  display: block;
  padding-left: 2px;
  white-space: pre;
  tab-size: 2;
}
.resource-note {
  margin: 10px 0 0;
  font-size: 0.78rem;
}
.resource-source {
  display: grid;
  gap: 10px;
}
.resource-link {
  grid-area: button;
  width: 100%;
  justify-content: center;
  align-self: flex-start;
  text-decoration: none;
}

/* API guide page */
.guide-page {
  max-width: 1120px;
}
.guide-hud {
  justify-content: space-between;
}
.guide-brand {
  text-decoration: none;
  color: inherit;
}
.guide-home {
  text-decoration: none;
  white-space: nowrap;
}
.guide-shell {
  display: grid;
  gap: 18px;
  min-width: 0;
}
.guide-hero {
  padding: 24px;
  min-width: 0;
}
.guide-title {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  line-height: 1;
  color: var(--navy);
  text-shadow: 3px 3px 0 var(--yellow);
}
.guide-subtitle {
  margin: 0;
  max-width: 820px;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.55;
  color: var(--muted);
}
.guide-actions {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}
.guide-main-action {
  width: auto;
  text-decoration: none;
}
.guide-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 18px;
}
.guide-card {
  background: var(--white);
  border: 3px solid var(--navy);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
  min-width: 0;
  color: var(--muted);
  font-weight: 650;
  line-height: 1.55;
}
.guide-card p {
  margin: 0 0 12px;
}
.guide-card p:last-child {
  margin-bottom: 0;
}
.guide-card p code,
.guide-list code,
.guide-subtitle code {
  overflow-wrap: anywhere;
  word-break: break-word;
}
.guide-section-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 1.35rem;
  color: var(--navy);
}
.guide-callout {
  background: linear-gradient(160deg, #E1F5FE, var(--cream));
}
.guide-callout.warn {
  background: linear-gradient(160deg, #FFF8E7, #FFE3EA);
}
.guide-list {
  margin-top: 0;
}
.guide-table-wrap {
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.guide-table {
  width: 100%;
  min-width: 680px;
  border-collapse: separate;
  border-spacing: 0;
  overflow: hidden;
  border: 3px solid var(--navy);
  border-radius: 14px;
  background: var(--cream);
}
.guide-table th,
.guide-table td {
  padding: 10px 12px;
  border-bottom: 2px solid var(--navy);
  border-right: 2px solid var(--navy);
  text-align: left;
  vertical-align: top;
}
.guide-table th {
  background: var(--yellow);
  color: var(--navy);
  font-family: var(--font-display);
  font-weight: 800;
}
.guide-table tr:last-child td {
  border-bottom: 0;
}
.guide-table th:last-child,
.guide-table td:last-child {
  border-right: 0;
}
.bottom-actions {
  margin-top: 14px;
}

/* ── Board layout ────────────────────────────────── */
.board-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 16px;
  align-items: start;
}
.board-layout.has-detail {
  grid-template-columns: 260px 1fr 340px;
}

.panel-title {
  font-family: var(--font-display);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-bottom: 8px;
}

.mailbox-panel,
.inbox-panel,
.detail-panel {
  background: var(--white);
  border: 3px solid var(--navy);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 14px;
  min-height: 120px;
}

.mailbox-card {
  background: linear-gradient(160deg, #E1F5FE, var(--cream));
  border: 3px solid var(--navy);
  border-radius: var(--radius-sm);
  padding: 14px;
  margin-bottom: 14px;
}
.mailbox-addr {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  word-break: break-all;
  color: var(--navy);
  line-height: 1.3;
  margin-bottom: 10px;
  user-select: all;
}
.mailbox-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 12px;
}
.chip {
  display: inline-block;
  background: var(--green);
  border: 2px solid var(--navy);
  border-radius: var(--radius-pill);
  padding: 2px 10px;
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--navy);
}
.chip-muted {
  background: var(--cream);
  color: var(--muted);
}
.mailbox-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.mailbox-actions .btn-ghost {
  grid-column: 1 / -1;
}

.tips-card {
  background: var(--cream);
  border: 2px dashed var(--navy);
  border-radius: var(--radius-sm);
  padding: 12px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--muted);
  line-height: 1.45;
}
.tips-card p { margin: 0 0 8px; }
.tips-card p:last-child { margin: 0; }
.tip-warn { color: var(--coral-hot); }

/* Inbox */
.inbox-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}
.auto-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 800;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
}
.auto-toggle input {
  width: 16px;
  height: 16px;
  accent-color: var(--green-hot);
}

.empty-state {
  position: relative;
  text-align: center;
  padding: 48px 16px;
  color: var(--muted);
}
.empty-art {
  font-size: 3.2rem;
  margin-bottom: 8px;
  filter: drop-shadow(3px 3px 0 var(--navy));
}
.empty-state h3 {
  margin: 0 0 6px;
  font-family: var(--font-display);
  color: var(--navy);
  font-size: 1.3rem;
}
.empty-state p {
  margin: 0;
  font-weight: 600;
}
.pulse-ring {
  position: absolute;
  left: 50%;
  top: 36px;
  width: 64px;
  height: 64px;
  margin-left: -32px;
  border: 3px solid var(--sky);
  border-radius: 50%;
  animation: ring 2s ease-out infinite;
  opacity: 0;
  pointer-events: none;
}
@keyframes ring {
  0% { transform: scale(0.6); opacity: 0.7; }
  100% { transform: scale(1.8); opacity: 0; }
}

.inbox-list {
  list-style: none;
  margin: 0;
  padding: 0;
  max-height: min(62vh, 560px);
  overflow-y: auto;
}
.mail-item {
  display: grid;
  grid-template-columns: 10px 1fr auto;
  gap: 10px;
  align-items: start;
  padding: 12px;
  border: 2px solid var(--navy);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  background: var(--cream);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: transform 0.08s, background 0.15s;
}
.mail-item:hover {
  transform: translateY(-2px);
  background: var(--white);
}
.mail-item.is-active {
  background: #E3F2FD;
  border-color: var(--sky-deep);
}
.mail-item.is-new {
  animation: mail-pop 0.45s cubic-bezier(.2,1.4,.4,1);
  background: #FFF9C4;
}
@keyframes mail-pop {
  0% { transform: scale(0.92); }
  60% { transform: scale(1.03); }
  100% { transform: scale(1); }
}
.mail-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--coral);
  border: 2px solid var(--navy);
  margin-top: 6px;
}
.mail-item.read .mail-dot {
  background: var(--muted);
  opacity: 0.4;
}
.mail-from {
  font-size: 0.78rem;
  font-weight: 800;
  color: var(--muted);
  margin-bottom: 2px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.mail-subject {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1rem;
  color: var(--navy);
  margin-bottom: 2px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.mail-preview {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.mail-time {
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--muted);
  white-space: nowrap;
  padding-top: 4px;
}

/* Detail */
.detail-panel {
  display: flex;
  flex-direction: column;
  max-height: min(70vh, 640px);
}
.detail-panel[hidden] { display: none !important; }
.detail-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}
.btn-close-detail {
  flex-shrink: 0;
  background: var(--coral) !important;
  color: var(--white);
  font-weight: 800;
}
.detail-subject {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 8px;
  word-break: break-word;
}
.detail-row {
  display: flex;
  gap: 8px;
  font-size: 0.82rem;
  margin-bottom: 4px;
}
.detail-row span {
  min-width: 40px;
  font-weight: 800;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.detail-row strong {
  font-weight: 700;
  color: var(--navy);
  word-break: break-all;
}
.detail-body {
  flex: 1;
  margin-top: 10px;
  border: 2px solid var(--navy);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--white);
  min-height: 220px;
}
.detail-body iframe {
  width: 100%;
  height: 100%;
  min-height: 280px;
  border: 0;
  background: white;
}
.detail-body pre {
  margin: 0;
  padding: 12px;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--navy);
  max-height: 360px;
  overflow: auto;
}

/* Toast / loading */
.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%) translateY(20px);
  background: var(--navy);
  color: var(--white);
  border: 3px solid var(--yellow);
  border-radius: var(--radius-pill);
  padding: 12px 22px;
  font-weight: 800;
  font-size: 0.95rem;
  box-shadow: 0 8px 0 rgba(0,0,0,0.15);
  z-index: 50;
  opacity: 0;
  transition: opacity 0.2s, transform 0.2s;
  max-width: min(90vw, 420px);
  text-align: center;
}
.toast.is-show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.toast.good { background: #1B5E20; border-color: var(--green); }
.toast.bad  { background: #B71C1C; border-color: var(--coral); }

.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(13, 27, 76, 0.45);
  display: grid;
  place-items: center;
  z-index: 60;
  backdrop-filter: blur(2px);
}
.loading-overlay[hidden] { display: none !important; }
.spinner {
  width: 56px;
  height: 56px;
  border: 5px solid var(--white);
  border-top-color: var(--yellow);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  box-shadow: 0 4px 0 var(--navy);
}
@keyframes spin { to { transform: rotate(360deg); } }
#loading-text {
  color: var(--white);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  margin: 12px 0 0;
  text-shadow: 2px 2px 0 var(--navy);
}

.site-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 8px 16px 24px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--navy);
  opacity: 0.7;
}
.site-footer .sep { margin: 0 6px; }

/* Responsive — PC + tablet + mobile */
@media (max-width: 1100px) {
  .board-layout.has-detail {
    grid-template-columns: 240px 1fr minmax(280px, 32%);
  }
  .hero-inner {
    gap: 24px;
  }
}

/* 平板：主内容仍全宽，hero 可单栏 */
@media (max-width: 900px) {
  .app {
    padding: 12px 12px 40px;
  }

  .hero-card {
    padding: 20px 16px 18px;
    border-radius: 22px;
  }
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  .hero-right {
    padding: 16px;
  }
  .hero-resources {
    margin-top: 12px;
    gap: 10px;
  }
  .resource-body {
    padding: 10px 12px 12px;
  }
  .resource-card {
    padding: 10px;
  }
  .guide-grid {
    grid-template-columns: 1fr;
  }
  .guide-hero,
  .guide-card {
    padding: 16px;
  }
  .hero-title {
    font-size: 2.2rem;
  }

  .board-layout,
  .board-layout.has-detail {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .mailbox-panel { order: 1; }
  .inbox-panel { order: 2; }

  .mailbox-actions {
    grid-template-columns: 1fr 1fr 1fr;
  }
  .mailbox-actions .btn-ghost {
    grid-column: auto;
  }

  .detail-panel {
    position: fixed;
    inset: 0;
    z-index: 40;
    max-height: none;
    height: 100%;
    border-radius: 0;
    border-width: 0;
    box-shadow: none;
    padding: 12px 12px calc(12px + env(safe-area-inset-bottom, 0px));
    animation: slide-up 0.28s cubic-bezier(.2,1.1,.4,1);
  }
  @keyframes slide-up {
    from { transform: translateY(24px); opacity: 0.6; }
    to   { transform: none; opacity: 1; }
  }
  .detail-body {
    min-height: 0;
    flex: 1;
  }
  .detail-body iframe {
    min-height: 50vh;
  }

  body.detail-open {
    overflow: hidden;
  }
}

@media (max-width: 640px) {
  .hud {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 8px 10px;
    padding: 10px;
    border-radius: 14px;
    align-items: center;
  }
  .brand {
    min-width: 0;
    grid-column: 1;
  }
  .brand-mark {
    width: 40px;
    height: 40px;
    font-size: 22px;
    border-radius: 12px;
  }
  .brand-title {
    font-size: 1.15rem;
  }
  .brand-tag {
    display: none;
  }

  .hud-toggles {
    grid-column: 2;
    gap: 6px;
  }
  .icon-btn {
    width: 40px;
    height: 40px;
    touch-action: manipulation;
  }

  .hud-metrics {
    grid-column: 1 / -1;
    width: 100%;
    justify-content: stretch;
    gap: 6px;
    flex: none;
  }
  .metric {
    min-width: 0;
    flex: 1;
    padding: 6px 4px;
    box-shadow: 0 2px 0 var(--navy);
  }
  .metric-value {
    font-size: 1.05rem;
  }
  .metric-value.sm {
    font-size: 0.8rem;
  }
  .metric-status {
    min-width: 0;
  }
  .metric-label {
    font-size: 0.58rem;
  }

  .hero-title {
    font-size: 1.9rem;
    text-shadow: 2px 2px 0 var(--yellow);
  }
  .hero-tagline {
    font-size: 0.92rem;
  }
  .rules li {
    font-size: 0.86rem;
    padding: 9px 10px;
  }
  .btn-play {
    font-size: 1.05rem;
    padding: 14px 18px;
    min-height: 52px;
  }
  .hero-resources {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .resource-card {
    grid-template-columns: 42px minmax(0, 1fr);
  }
  .resource-summary,
  .resource-header,
  .resource-body,
  .resource-source {
    padding-left: 0;
    padding-right: 0;
  }
  .resource-card.resource-api {
    padding-left: 12px;
    padding-right: 12px;
  }
  .resource-card.resource-source {
    padding-left: 12px;
    padding-right: 12px;
  }
  .resource-title {
    font-size: 0.95rem;
  }
  .resource-subtitle {
    font-size: 0.72rem;
  }
  .resource-text,
  .api-endpoints {
    font-size: 0.8rem;
  }
  .api-code {
    font-size: 0.7rem;
    padding: 10px;
  }
  .guide-hud {
    align-items: center;
    grid-template-columns: minmax(0, 1fr) auto;
  }
  .guide-brand {
    min-width: 0;
  }
  .guide-home {
    min-height: 40px;
    padding: 8px 12px;
  }
  .guide-title {
    font-size: 1.9rem;
    line-height: 1.08;
  }
  .guide-subtitle {
    font-size: 0.9rem;
  }
  .guide-actions {
    display: grid;
    grid-template-columns: 1fr;
  }
  .guide-actions .btn {
    width: 100%;
  }
  .guide-card {
    padding: 12px;
    box-shadow: var(--shadow-sm);
  }
  .codebox-head {
    padding: 7px 8px;
  }
  .codebox-title {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .codebox-body {
    font-size: 0.68rem;
  }
  .codebox-body li {
    grid-template-columns: 2.7em max-content;
    gap: 8px;
    padding-right: 10px;
  }
  .guide-table {
    min-width: 620px;
  }
  .guide-section-title {
    font-size: 1.1rem;
  }
  .btn {
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
  }

  .field-input,
  .field-select {
    font-size: 16px;
    padding: 12px 12px;
    min-height: 48px;
  }

  .mailbox-card {
    padding: 12px;
  }
  .mailbox-addr {
    font-size: 0.95rem;
  }
  .mailbox-actions {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }
  .mailbox-actions .btn-ghost {
    grid-column: 1 / -1;
  }
  .btn-secondary,
  .btn-ghost {
    min-height: 44px;
    font-size: 0.88rem;
    padding: 10px 8px;
  }

  .inbox-list {
    max-height: none;
  }
  .mail-item {
    padding: 12px 10px;
    min-height: 64px;
  }
  .mail-subject {
    font-size: 0.95rem;
    white-space: normal;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
  }
  .mail-preview {
    white-space: normal;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
  }

  .empty-state {
    padding: 36px 12px;
  }
  .empty-art {
    font-size: 2.6rem;
  }

  .toast {
    bottom: calc(16px + env(safe-area-inset-bottom, 0px));
    left: 12px;
    right: 12px;
    max-width: none;
    transform: translateY(20px);
    font-size: 0.9rem;
    padding: 12px 14px;
  }
  .toast.is-show {
    transform: translateY(0);
  }

  .site-footer {
    font-size: 0.7rem;
    padding-bottom: calc(16px + env(safe-area-inset-bottom, 0px));
  }
  .site-footer .sep {
    display: none;
  }

  .orb-a { width: 100px; height: 100px; }
  .orb-b { width: 70px; height: 70px; }
  .orb-c { width: 50px; height: 50px; opacity: 0.35; }
}

@media (max-width: 380px) {
  .hero-title { font-size: 1.7rem; }
  .rules { display: none; }
  .guide-hud {
    grid-template-columns: 1fr;
  }
  .guide-home {
    width: 100%;
  }
  .guide-title {
    font-size: 1.65rem;
  }
  .guide-table {
    min-width: 560px;
  }
}

@media (max-height: 480px) and (orientation: landscape) {
  .rules { display: none; }
  .hero-tagline { margin-bottom: 10px; }
  .empty-state { padding: 20px 12px; }
}

/* 大屏 PC：与顶栏同宽的宽布局 */
@media (min-width: 1101px) {
  .board-layout {
    grid-template-columns: 320px 1fr;
  }
  .board-layout.has-detail {
    grid-template-columns: 300px 1fr 380px;
  }
  .inbox-list {
    max-height: min(68vh, 640px);
  }
  .hero-title {
    font-size: 3rem;
  }
}

@media (hover: none) {
  .btn:hover { transform: none; }
  .btn:active {
    transform: translateY(3px);
    box-shadow: 0 2px 0 var(--navy);
  }
  .mail-item:hover {
    transform: none;
  }
  .mail-item:active {
    background: #E3F2FD;
  }
}