/* =========================================================
   ATRI · 亚托莉 宣传页
   ========================================================= */

:root {
  --bg: #04101d;
  --bg-2: #071a2c;
  --panel: rgba(11, 33, 54, 0.66);
  --panel-solid: #0b2136;
  --border: rgba(126, 208, 255, 0.16);
  --border-strong: rgba(126, 208, 255, 0.34);
  --text: #eaf6ff;
  --text-dim: #9fb6c9;
  --text-faint: #6d8399;
  --cyan: #79e6ff;
  --cyan-strong: #2fc9ef;
  --peach: #ffb59f;
  --glow: rgba(74, 196, 255, 0.28);
  --radius: 18px;
  --shadow: 0 24px 60px -28px rgba(0, 0, 0, 0.85);
  --max: 1120px;
  --font: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-round: "Zen Maru Gothic", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --transition: 220ms ease;
}

/* ---------- 海面（浅色）主题 ---------- */
html.theme-day {
  --bg: #eaf7fd;
  --bg-2: #d3edf8;
  --panel: rgba(255, 255, 255, 0.72);
  --panel-solid: #ffffff;
  --border: rgba(20, 90, 130, 0.16);
  --border-strong: rgba(20, 90, 130, 0.32);
  --text: #0a2537;
  --text-dim: #41657c;
  --text-faint: #6c8a9c;
  --cyan: #0f9dc4;
  --cyan-strong: #0a7fa0;
  --peach: #d9714f;
  --glow: rgba(60, 170, 210, 0.22);
  --shadow: 0 24px 60px -34px rgba(9, 48, 70, 0.45);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  background: radial-gradient(1200px 700px at 15% -10%, rgba(47, 201, 239, 0.14), transparent 60%),
              radial-gradient(900px 600px at 90% 10%, rgba(255, 181, 159, 0.10), transparent 55%),
              linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 55%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.75;
  overflow-x: hidden;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

::selection { background: rgba(121, 230, 255, 0.35); color: #eaf6ff; }

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

img, svg { display: block; max-width: 100%; }

/* ---------- 背景气泡与极光 ---------- */
.bubbles {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
.bubble {
  position: absolute;
  bottom: -10vh;
  border-radius: 50%;
  border: 1px solid rgba(170, 235, 255, 0.45);
  background: radial-gradient(circle at 32% 28%, rgba(255, 255, 255, 0.35), rgba(121, 230, 255, 0.06) 55%, transparent 72%);
  box-shadow: 0 0 18px rgba(74, 196, 255, 0.12) inset;
  animation: rise linear infinite;
  opacity: 0;
}
html.theme-day .bubble {
  border-color: rgba(20, 120, 160, 0.22);
  background: radial-gradient(circle at 32% 28%, rgba(255, 255, 255, 0.85), rgba(20, 120, 160, 0.05) 60%, transparent 72%);
}
@keyframes rise {
  0%   { transform: translate3d(0, 0, 0) scale(0.9); opacity: 0; }
  8%   { opacity: 0.75; }
  90%  { opacity: 0.35; }
  100% { transform: translate3d(var(--drift, 20px), -118vh, 0) scale(1.08); opacity: 0; }
}

.aurora {
  position: fixed;
  inset: -20% -10% auto -10%;
  height: 70vh;
  background:
    radial-gradient(50% 60% at 30% 10%, rgba(47, 201, 239, 0.16), transparent 70%),
    radial-gradient(45% 55% at 75% 0%, rgba(255, 181, 159, 0.10), transparent 70%);
  filter: blur(30px);
  pointer-events: none;
  z-index: 0;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 14px clamp(18px, 4vw, 44px);
  backdrop-filter: blur(14px);
  background: linear-gradient(180deg, rgba(4, 16, 29, 0.82), rgba(4, 16, 29, 0.35));
  border-bottom: 1px solid rgba(126, 208, 255, 0.08);
}
html.theme-day .site-header {
  background: linear-gradient(180deg, rgba(234, 247, 253, 0.9), rgba(234, 247, 253, 0.45));
  border-bottom-color: rgba(20, 90, 130, 0.1);
}

.brand { display: flex; align-items: center; gap: 10px; font-family: var(--font-round); letter-spacing: 0.12em; }
.brand-dot {
  width: 10px; height: 10px; border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #ffffff, var(--cyan) 55%, var(--cyan-strong));
  box-shadow: 0 0 12px var(--cyan), 0 0 26px rgba(121, 230, 255, 0.5);
}
.brand-text { font-weight: 700; font-size: 15px; display: flex; align-items: baseline; gap: 8px; }
.brand-text small { font-family: var(--font); font-size: 11px; color: var(--text-dim); letter-spacing: 0.2em; }

.nav { display: flex; gap: 22px; margin-left: auto; font-size: 13.5px; color: var(--text-dim); }
.nav a { position: relative; transition: color var(--transition); padding: 4px 0; }
.nav a::after {
  content: ""; position: absolute; left: 0; bottom: 0; width: 0; height: 1px;
  background: var(--cyan); transition: width var(--transition);
}
.nav a:hover { color: var(--text); }
.nav a:hover::after { width: 100%; }

.header-actions { display: flex; align-items: center; gap: 10px; }

.theme-toggle {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 8px 13px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text-dim);
  font-size: 12.5px;
  font-family: var(--font);
  cursor: pointer;
  transition: all var(--transition);
}
.theme-toggle:hover { border-color: var(--border-strong); color: var(--text); }
.theme-icon { font-size: 13px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font);
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), border-color var(--transition);
  white-space: nowrap;
}
.btn:active { transform: translateY(1px) scale(0.99); }

.btn-primary {
  background: linear-gradient(135deg, #8ef0ff 0%, var(--cyan-strong) 60%, #1d9fc4 100%);
  color: #04202c;
  box-shadow: 0 12px 34px -12px rgba(47, 201, 239, 0.65), inset 0 1px 0 rgba(255, 255, 255, 0.55);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 18px 44px -12px rgba(47, 201, 239, 0.8), inset 0 1px 0 rgba(255, 255, 255, 0.6); }
html.theme-day .btn-primary { color: #ffffff; }

.btn-ghost {
  background: var(--panel);
  border-color: var(--border-strong);
  color: var(--text);
  backdrop-filter: blur(8px);
}
.btn-ghost:hover { border-color: var(--cyan); color: var(--cyan); transform: translateY(-2px); }

.btn-sm { padding: 9px 18px; font-size: 12.5px; }
.btn-lg { padding: 17px 34px; font-size: 16px; }
.btn-icon { font-size: 17px; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  isolation: isolate;
  padding: clamp(46px, 8vh, 90px) clamp(18px, 4vw, 44px) 130px;
  min-height: calc(100vh - 70px);
  display: flex;
  align-items: center;
  z-index: 1;
}
.hero-inner {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: clamp(30px, 5vw, 70px);
  align-items: center;
}

.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  margin: 0 0 20px;
  font-size: 12px; letter-spacing: 0.22em;
  color: var(--text-dim);
  border: 1px solid var(--border);
  padding: 7px 16px;
  border-radius: 999px;
  background: var(--panel);
  backdrop-filter: blur(8px);
}
.pulse {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 0 rgba(121, 230, 255, 0.6);
  animation: pulse 2.4s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(121, 230, 255, 0.55); }
  70% { box-shadow: 0 0 0 9px rgba(121, 230, 255, 0); }
  100% { box-shadow: 0 0 0 0 rgba(121, 230, 255, 0); }
}

.hero-title { margin: 0; line-height: 1; }
.title-latin {
  display: block;
  font-family: "Times New Roman", "Songti SC", serif;
  font-size: clamp(72px, 12vw, 148px);
  font-weight: 700;
  letter-spacing: 0.06em;
  background: linear-gradient(180deg, #ffffff 0%, #b9ecff 38%, var(--cyan) 78%, #1f9fc7 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 8px 34px rgba(47, 201, 239, 0.35));
}
.title-cn {
  display: block;
  margin-top: 6px;
  font-family: var(--font-round);
  font-size: clamp(22px, 3.2vw, 32px);
  letter-spacing: 0.5em;
  color: var(--text-dim);
  font-weight: 500;
}

.hero-tagline {
  margin: 26px 0 10px;
  font-family: var(--font-round);
  font-size: clamp(17px, 2.1vw, 21px);
  color: var(--cyan);
  letter-spacing: 0.06em;
  min-height: 1.6em;
}
.hero-tagline::after { content: "▌"; opacity: 0.55; animation: blink 1.1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }

.hero-desc { margin: 0 0 30px; color: var(--text-dim); font-size: clamp(14px, 1.6vw, 15.5px); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 13px; }
.hero-hint { margin: 16px 0 0; font-size: 12px; color: var(--text-faint); }
.hero-hint b { color: var(--text-dim); font-weight: 600; }

/* ---------- Hero visual ---------- */
.hero-visual { position: relative; min-height: 500px; }

.capsule {
  position: relative;
  width: min(250px, 58vw);
  margin: 10px auto 0;
  filter: drop-shadow(0 30px 50px rgba(0, 0, 0, 0.45));
}
.capsule-glass {
  position: relative;
  aspect-ratio: 1 / 1.32;
  border-radius: 48% 48% 42% 42% / 40% 40% 46% 46%;
  border: 1.5px solid rgba(190, 246, 255, 0.6);
  background:
    radial-gradient(60% 55% at 40% 30%, rgba(200, 250, 255, 0.28), rgba(30, 120, 160, 0.12) 55%, rgba(6, 26, 42, 0.65) 100%),
    linear-gradient(160deg, rgba(121, 230, 255, 0.10), rgba(4, 16, 29, 0.2));
  box-shadow: inset 0 0 50px rgba(121, 230, 255, 0.18), 0 0 60px rgba(74, 196, 255, 0.16);
  overflow: hidden;
  animation: float 7s ease-in-out infinite;
}
.light-core {
  position: absolute; left: 50%; top: 50%;
  width: 54%; aspect-ratio: 1;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: radial-gradient(circle at 42% 38%, #ffffff 0%, #bff4ff 22%, rgba(121, 230, 255, 0.55) 48%, rgba(47, 201, 239, 0.08) 72%, transparent 78%);
  filter: blur(1px);
  animation: corePulse 4.5s ease-in-out infinite;
}
@keyframes corePulse {
  0%, 100% { opacity: 0.85; transform: translate(-50%, -50%) scale(1); }
  50% { opacity: 1; transform: translate(-50%, -50%) scale(1.06); }
}
.capsule-rings { position: absolute; inset: 0; }
.capsule-rings i {
  position: absolute; left: 50%; top: 50%;
  border: 1px solid rgba(160, 235, 255, 0.22);
  border-radius: 50%;
  transform: translate(-50%, -50%);
}
.capsule-rings i:nth-child(1) { width: 62%; aspect-ratio: 1; animation: ring 8s linear infinite; }
.capsule-rings i:nth-child(2) { width: 78%; aspect-ratio: 1; border-style: dashed; animation: ring 12s linear infinite reverse; }
.capsule-rings i:nth-child(3) { width: 92%; aspect-ratio: 1; border-color: rgba(160, 235, 255, 0.12); animation: ring 18s linear infinite; }
@keyframes ring { to { transform: translate(-50%, -50%) rotate(360deg); } }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-14px); } }

.capsule-base {
  width: 56%; height: 30px; margin: -6px auto 0;
  border-radius: 0 0 40% 40% / 0 0 100% 100%;
  background: linear-gradient(180deg, rgba(160, 235, 255, 0.4), rgba(10, 40, 60, 0.08));
  filter: blur(0.4px);
  position: relative;
}
.capsule-base::after {
  content: "ATRI · CAPSULE-02";
  position: absolute;
  left: 50%; top: 62%;
  transform: translate(-50%, -50%);
  font-family: var(--font-round);
  font-size: 8.5px;
  letter-spacing: 0.28em;
  white-space: nowrap;
  color: rgba(180, 240, 255, 0.55);
}
.capsule-glass::after {
  content: "";
  position: absolute;
  left: 16%; top: 10%;
  width: 26%; height: 52%;
  border-radius: 50%;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.35), rgba(255, 255, 255, 0));
  filter: blur(6px);
  transform: rotate(-14deg);
  pointer-events: none;
}

.chat-card {
  position: absolute;
  padding: 12px 15px;
  width: min(250px, 62vw);
  border-radius: 16px;
  border: 1px solid var(--border-strong);
  background: var(--panel);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
  font-size: 12.5px;
  color: var(--text-dim);
  line-height: 1.65;
}
.chat-card p { margin: 4px 0 0; }
.chat-card b { color: var(--cyan); }
.chat-name { font-size: 11px; color: var(--cyan); letter-spacing: 0.08em; }
.chat-me {
  display: inline-block; margin-top: 7px; padding: 3px 10px;
  border-radius: 999px; background: rgba(255, 181, 159, 0.12);
  color: var(--peach); font-size: 11.5px;
}
.chat-card-a { left: -16%; top: 4%; animation: floatCard 8s ease-in-out infinite; }
.chat-card-b { right: -12%; bottom: 4%; animation: floatCard 9s ease-in-out infinite reverse; }
@keyframes floatCard {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.float-chip {
  position: absolute;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 11.5px;
  color: var(--text-dim);
  border: 1px solid var(--border);
  background: var(--panel);
  backdrop-filter: blur(8px);
  animation: floatCard 7s ease-in-out infinite;
}
.chip-1 { left: -2%; bottom: 26%; animation-delay: -2s; }
.chip-2 { right: 4%; top: 0%; animation-delay: -4s; }
.chip-3 { left: 62%; bottom: -4%; animation-delay: -6s; }

.hero-waves {
  position: absolute; left: 0; right: 0; bottom: -1px; height: 120px;
  z-index: -1;
  opacity: 0.55;
}
.hero-waves svg { width: 100%; height: 100%; }
.wave-1 { fill: rgba(121, 230, 255, 0.07); }
.wave-2 { fill: rgba(121, 230, 255, 0.045); }
html.theme-day .wave-1 { fill: rgba(15, 120, 160, 0.08); }
html.theme-day .wave-2 { fill: rgba(15, 120, 160, 0.05); }

/* ---------- Sections ---------- */
.section {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(60px, 9vw, 110px) clamp(18px, 4vw, 44px);
}
.section-head { max-width: 720px; margin-bottom: clamp(30px, 4vw, 52px); }
.section-kicker {
  display: inline-block;
  font-size: 11.5px;
  letter-spacing: 0.26em;
  color: var(--cyan);
  margin-bottom: 14px;
}
.section-head h2 {
  margin: 0 0 12px;
  font-family: var(--font-round);
  font-size: clamp(26px, 4vw, 40px);
  line-height: 1.35;
  letter-spacing: 0.03em;
  font-weight: 700;
}
.section-sub { margin: 0; color: var(--text-dim); font-size: clamp(13.5px, 1.6vw, 15px); }

/* ---------- About ---------- */
.about-grid { display: grid; grid-template-columns: 1.25fr 1fr; gap: clamp(24px, 4vw, 48px); align-items: start; }
.about-text p { margin: 0 0 18px; color: var(--text-dim); font-size: clamp(14px, 1.6vw, 15.5px); }
.about-text p:first-child { font-size: clamp(16px, 2vw, 19px); color: var(--text); }
.about-card {
  padding: clamp(24px, 3vw, 34px);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: linear-gradient(160deg, rgba(121, 230, 255, 0.09), rgba(255, 181, 159, 0.05));
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.about-card::before {
  content: "“";
  position: absolute; right: 18px; top: -26px;
  font-size: 120px;
  color: rgba(121, 230, 255, 0.12);
  font-family: Georgia, serif;
}
.about-card blockquote {
  margin: 0 0 22px;
  font-family: var(--font-round);
  font-size: clamp(15px, 1.9vw, 17.5px);
  line-height: 1.95;
  color: var(--text);
}
.about-card-foot { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-size: 11.5px;
  padding: 4px 11px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  color: var(--text-dim);
  background: rgba(121, 230, 255, 0.05);
}

/* ---------- Features ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(14px, 2vw, 22px);
}
.feature {
  padding: clamp(22px, 2.6vw, 30px);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--panel);
  backdrop-filter: blur(10px);
  transition: transform 260ms ease, border-color 260ms ease, background 260ms ease;
}
.feature:hover {
  transform: translateY(-6px);
  border-color: var(--border-strong);
  background: linear-gradient(160deg, rgba(121, 230, 255, 0.09), var(--panel));
}
.feature-ico {
  width: 46px; height: 46px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 14px;
  border-radius: 14px;
  color: var(--cyan);
  background: rgba(121, 230, 255, 0.09);
  border: 1px solid rgba(121, 230, 255, 0.22);
  box-shadow: inset 0 0 18px rgba(121, 230, 255, 0.08);
}
.feature-ico svg { width: 24px; height: 24px; }
html.theme-day .feature-ico { background: rgba(15, 157, 196, 0.08); border-color: rgba(20, 110, 150, 0.22); }
.feature h3 { margin: 0 0 8px; font-size: 16.5px; font-family: var(--font-round); letter-spacing: 0.02em; }
.feature p { margin: 0; color: var(--text-dim); font-size: 13.5px; }

/* ---------- Timeline ---------- */
.timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 0;
  position: relative;
  display: grid;
  gap: 10px;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 86px; top: 10px; bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, transparent, var(--border-strong) 12%, var(--border-strong) 88%, transparent);
}
.timeline li {
  display: grid;
  grid-template-columns: 86px 1fr;
  align-items: start;
  gap: 26px;
  padding: 16px 0;
  position: relative;
}
.tl-day {
  font-family: var(--font-round);
  font-size: 13px;
  color: var(--cyan);
  letter-spacing: 0.06em;
  padding-top: 2px;
  text-align: right;
}
.timeline li::before {
  content: "";
  position: absolute;
  left: 82px; top: 26px;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--cyan);
  box-shadow: 0 0 12px rgba(121, 230, 255, 0.6);
}
.tl-body h3 { margin: 0 0 6px; font-size: 17px; font-family: var(--font-round); }
.tl-body p { margin: 0; color: var(--text-dim); font-size: 13.8px; max-width: 620px; }
.journey-note { margin: 26px 0 0 112px; font-size: 12.5px; color: var(--text-faint); }

/* ---------- Steps ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(14px, 2vw, 22px);
  margin-bottom: clamp(40px, 6vw, 70px);
}
.step {
  position: relative;
  padding: clamp(24px, 3vw, 32px);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--panel);
  backdrop-filter: blur(10px);
}
.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px; height: 38px;
  border-radius: 50%;
  font-family: var(--font-round);
  font-weight: 700;
  color: #04202c;
  background: linear-gradient(135deg, #b8f4ff, var(--cyan-strong));
  margin-bottom: 16px;
  box-shadow: 0 8px 22px -8px rgba(47, 201, 239, 0.7);
}
.step h3 { margin: 0 0 8px; font-size: 17px; font-family: var(--font-round); }
.step p { margin: 0; color: var(--text-dim); font-size: 13.5px; }
.step p b { color: var(--cyan); }

/* ---------- Join panel ---------- */
.join-panel {
  position: relative;
  overflow: hidden;
  text-align: center;
  padding: clamp(40px, 6vw, 76px) clamp(20px, 4vw, 56px);
  border-radius: calc(var(--radius) + 8px);
  border: 1px solid var(--border-strong);
  background:
    radial-gradient(70% 120% at 50% 0%, rgba(47, 201, 239, 0.18), transparent 60%),
    linear-gradient(180deg, rgba(11, 33, 54, 0.85), rgba(4, 16, 29, 0.9));
  box-shadow: var(--shadow);
}
html.theme-day .join-panel {
  background:
    radial-gradient(70% 120% at 50% 0%, rgba(47, 201, 239, 0.22), transparent 60%),
    linear-gradient(180deg, #ffffff, #eaf7fd);
}
.join-glow {
  position: absolute;
  left: 50%; top: -120px;
  width: 520px; height: 260px;
  transform: translateX(-50%);
  background: radial-gradient(closest-side, rgba(121, 230, 255, 0.28), transparent 70%);
  filter: blur(20px);
  pointer-events: none;
}
.join-panel h2 { margin: 0 0 12px; font-family: var(--font-round); font-size: clamp(24px, 3.6vw, 34px); }
.join-panel > p { margin: 0 0 34px; color: var(--text-dim); font-size: 14.5px; }
.join-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 14px; }
.join-fallback { margin: 22px 0 0 !important; font-size: 12px; color: var(--text-faint); }

/* ---------- FAQ ---------- */
.faq-list { display: grid; gap: 12px; max-width: 820px; }
.faq-list details {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--panel);
  padding: 0 20px;
  transition: border-color var(--transition), background var(--transition);
}
.faq-list details[open] { border-color: var(--border-strong); background: linear-gradient(160deg, rgba(121, 230, 255, 0.06), var(--panel)); }
.faq-list summary {
  cursor: pointer;
  padding: 18px 0;
  font-size: 14.5px;
  font-weight: 600;
  list-style: none;
  position: relative;
  padding-right: 30px;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+";
  position: absolute; right: 2px; top: 50%;
  transform: translateY(-50%);
  color: var(--cyan);
  font-size: 18px;
  transition: transform var(--transition);
}
.faq-list details[open] summary::after { transform: translateY(-50%) rotate(45deg); }
.faq-list p { margin: 0; padding: 0 0 20px; color: var(--text-dim); font-size: 13.5px; }

/* ---------- Footer ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: 20px;
  padding: 46px clamp(18px, 4vw, 44px) 60px;
  border-top: 1px solid var(--border);
  background: linear-gradient(180deg, transparent, rgba(4, 16, 29, 0.6));
}
html.theme-day .site-footer { background: linear-gradient(180deg, transparent, rgba(20, 90, 130, 0.06)); }
.footer-inner { max-width: var(--max); margin: 0 auto; text-align: center; }
.footer-brand {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--font-round);
  font-weight: 700;
  letter-spacing: 0.14em;
  margin-bottom: 14px;
}
.disclaimer {
  max-width: 720px;
  margin: 0 auto 12px;
  font-size: 12px;
  line-height: 1.9;
  color: var(--text-faint);
}
.footer-small { margin: 0; font-size: 12px; color: var(--text-faint); letter-spacing: 0.06em; }

/* ---------- Sticky join ---------- */
.sticky-join {
  position: fixed;
  right: clamp(14px, 2.4vw, 28px);
  bottom: clamp(14px, 2.4vw, 28px);
  z-index: 60;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 13px 22px;
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 700;
  color: #04202c;
  background: linear-gradient(135deg, #a9f2ff, var(--cyan-strong));
  box-shadow: 0 16px 40px -14px rgba(47, 201, 239, 0.8);
  transform: translateY(90px);
  opacity: 0;
  transition: all 320ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
html.theme-day .sticky-join { color: #ffffff; }
.sticky-join.show { transform: translateY(0); opacity: 1; }
.sticky-join:hover { transform: translateY(-3px); }
.sticky-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: #04202c;
  box-shadow: 0 0 8px rgba(4, 32, 44, 0.6);
}
html.theme-day .sticky-dot { background: #ffffff; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 34px;
  transform: translate(-50%, 24px);
  z-index: 80;
  padding: 11px 22px;
  border-radius: 999px;
  background: rgba(8, 26, 40, 0.92);
  border: 1px solid var(--border-strong);
  color: var(--text);
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transition: all 280ms ease;
  backdrop-filter: blur(10px);
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------- Reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 700ms ease, transform 700ms ease;
}
.reveal.in { opacity: 1; transform: translateY(0); }

/* ---------- noscript ---------- */
.noscript-tip {
  position: fixed;
  left: 50%; top: 12px;
  transform: translateX(-50%);
  z-index: 90;
  background: #ffb59f;
  color: #3a160c;
  padding: 10px 18px;
  border-radius: 12px;
  font-size: 13px;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { min-height: 380px; margin-top: 10px; }
  .chat-card-a { left: 0; }
  .chat-card-b { right: 0; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; }
  .nav { display: none; }
}

@media (max-width: 600px) {
  .feature-grid { grid-template-columns: 1fr; }
  .timeline::before { left: 62px; }
  .timeline li { grid-template-columns: 62px 1fr; gap: 16px; }
  .timeline li::before { left: 58px; }
  .tl-day { font-size: 12px; }
  .journey-note { margin-left: 78px; }
  .hero { padding-bottom: 100px; }
  .chat-card { width: 210px; font-size: 11.5px; }
  .header-actions .btn-sm { display: none; }
  .btn-lg { padding: 15px 24px; font-size: 14.5px; }
  .join-actions { flex-direction: column; }
  .join-actions .btn { width: 100%; }
  .brand-text small { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------- 海面主题：舱体与标题适配 ---------- */
html.theme-day .title-latin {
  background: linear-gradient(180deg, #0d6f8d 0%, #0f9dc4 42%, #2fc9ef 78%, #7fe4ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 6px 22px rgba(15, 157, 196, 0.25));
}
html.theme-day .capsule-glass {
  border-color: rgba(20, 110, 150, 0.35);
  background:
    radial-gradient(60% 55% at 40% 30%, rgba(255, 255, 255, 0.95), rgba(170, 225, 242, 0.45) 55%, rgba(205, 238, 248, 0.65) 100%),
    linear-gradient(160deg, rgba(255, 255, 255, 0.7), rgba(200, 235, 248, 0.5));
  box-shadow: inset 0 0 40px rgba(255, 255, 255, 0.7), 0 18px 40px rgba(9, 48, 70, 0.12);
}
html.theme-day .light-core {
  background: radial-gradient(circle at 42% 38%, #ffffff 0%, #eafcff 26%, rgba(47, 201, 239, 0.6) 52%, rgba(47, 201, 239, 0.06) 76%, transparent 80%);
}
html.theme-day .capsule-rings i { border-color: rgba(20, 110, 150, 0.2); }
html.theme-day .capsule-base {
  background: linear-gradient(180deg, rgba(175, 225, 240, 0.85), rgba(150, 200, 220, 0.2));
}
html.theme-day .capsule-base::after { color: rgba(20, 90, 130, 0.55); }
html.theme-day .hero-waves { opacity: 0.8; }
html.theme-day .toast { background: rgba(255, 255, 255, 0.95); color: var(--text); }

html.theme-day .btn-ghost { background: rgba(255, 255, 255, 0.85); border-color: rgba(20, 90, 130, 0.22); }
html.theme-day .theme-toggle { background: rgba(255, 255, 255, 0.85); }
html.theme-day .chat-card, html.theme-day .feature, html.theme-day .step, html.theme-day .faq-list details { background: rgba(255, 255, 255, 0.78); }