/* ============== 呼吸 · 深色典雅 ============== */

:root {
  --bg: #0a0e14;
  --bg-2: #0f1420;
  --fg: #e8e6e1;
  --fg-dim: #8a8680;
  --fg-mute: #5a574f;
  --accent: #c9b88a;        /* 柔和暖月光金 */
  --accent-dim: #7a6f52;
  --line: rgba(232,230,225,0.08);
  --glow: rgba(201,184,138,0.15);
  --font-serif: "Songti SC", "STSong", "Noto Serif CJK SC", "Source Han Serif SC",
                "思源宋体", "宋体", Georgia, serif;
  --font-sans:  -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0; padding: 0;
  height: 100%; width: 100%;
  overscroll-behavior: none;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-serif);
  font-weight: 300;
  letter-spacing: 0.04em;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}

.screen {
  position: fixed; inset: 0;
  display: flex; flex-direction: column;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
  transition: opacity 0.6s ease;
}
.screen.hidden { display: none; }

.close-btn {
  position: absolute; top: calc(env(safe-area-inset-top) + 18px); right: 22px;
  background: none; border: none; color: var(--fg-mute);
  font-size: 32px; font-weight: 200; cursor: pointer; z-index: 10;
  width: 44px; height: 44px; line-height: 1;
  transition: color 0.3s ease;
}
.close-btn:hover { color: var(--fg-dim); }

/* ============== 首次询问 ============== */
#intro { align-items: center; justify-content: center; background: var(--bg); }
.intro-inner { text-align: center; }
.intro-title {
  font-size: 14px; letter-spacing: 0.6em; color: var(--fg-mute);
  text-indent: 0.6em; margin-bottom: 40px;
}
.intro-sub { font-size: 22px; color: var(--fg-dim); margin-bottom: 56px; letter-spacing: 0.15em; }
.intro-btns { display: flex; flex-direction: column; gap: 20px; align-items: center; }
.intro-btn {
  width: 220px; padding: 18px 0;
  background: transparent; border: 1px solid var(--line);
  color: var(--fg); font-family: var(--font-serif);
  font-size: 18px; letter-spacing: 0.3em; text-indent: 0.3em;
  cursor: pointer; transition: all 0.4s ease;
}
.intro-btn:hover {
  border-color: var(--accent-dim);
  color: var(--accent);
  background: rgba(201,184,138,0.03);
}
.intro-hint { margin-top: 48px; font-size: 12px; color: var(--fg-mute); letter-spacing: 0.2em; }

/* ============== 主页 ============== */
#home { justify-content: space-between; }

.home-header {
  text-align: center; padding-top: 60px;
}
.brand {
  font-size: 22px;
  letter-spacing: 0.8em;
  text-indent: 0.8em;
  color: var(--fg-dim);
}

.home-main {
  flex: 1;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 44px;
}

.mode-btn {
  width: min(300px, 70vw);
  padding: 44px 0;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--fg);
  font-family: var(--font-serif);
  cursor: pointer;
  transition: all 0.6s cubic-bezier(.25,.1,.25,1);
  position: relative;
  overflow: hidden;
}
.mode-btn::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(circle at center, var(--glow) 0%, transparent 70%);
  opacity: 0; transition: opacity 0.6s ease;
}
.mode-btn:hover {
  border-color: var(--accent-dim);
  transform: translateY(-1px);
}
.mode-btn:hover::before { opacity: 1; }
.mode-btn:active { transform: scale(0.99); }

.mode-title {
  font-size: 32px;
  letter-spacing: 0.5em; text-indent: 0.5em;
  color: var(--fg);
  margin-bottom: 10px;
  position: relative;
}
.mode-sub {
  font-size: 13px;
  color: var(--fg-mute);
  letter-spacing: 0.3em; text-indent: 0.3em;
  position: relative;
}

.home-footer {
  text-align: center; padding-bottom: 40px;
}
.settings-btn {
  background: none; border: none; color: var(--fg-mute);
  font-family: var(--font-serif); font-size: 13px;
  letter-spacing: 0.4em; text-indent: 0.4em;
  padding: 12px 20px; cursor: pointer;
  transition: color 0.3s ease;
}
.settings-btn:hover { color: var(--fg-dim); }

/* ============== 练习界面 ============== */
#practice { align-items: center; justify-content: center; background: var(--bg); }

.practice-inner {
  display: flex; flex-direction: column; align-items: center;
  gap: 60px;
}
/* "吸气"/"呼气"文字 —— 带物理呼吸动效:
   letter-spacing 展开/收回,配合 opacity 渐变 */
.phase {
  font-size: 26px;
  color: var(--fg);
  min-height: 40px;
  opacity: 0;
  letter-spacing: 0.3em;
  text-indent: 0.3em;
  will-change: letter-spacing, opacity, transform;
  transition: opacity 0.8s ease;
}
.phase.visible { opacity: 0.9; }
/* 吸气动效:字间距展开 + 变亮 */
.phase.inhale-anim {
  animation: phase-inhale var(--phase-dur, 4s) cubic-bezier(.45,.05,.55,.95) forwards;
}
/* 呼气动效:字间距收回 + 变暗 */
.phase.exhale-anim {
  animation: phase-exhale var(--phase-dur, 8s) cubic-bezier(.45,.05,.55,.95) forwards;
}
@keyframes phase-inhale {
  0%   { opacity: 0.5; letter-spacing: 0.3em; text-indent: 0.3em; transform: translateY(4px); }
  100% { opacity: 1.0; letter-spacing: 0.7em; text-indent: 0.7em; transform: translateY(0); }
}
@keyframes phase-exhale {
  0%   { opacity: 1.0; letter-spacing: 0.7em; text-indent: 0.7em; transform: translateY(0); }
  100% { opacity: 0.45; letter-spacing: 0.3em; text-indent: 0.3em; transform: translateY(4px); }
}

.circle-wrap {
  width: 320px; height: 320px;
  display: flex; align-items: center; justify-content: center;
  position: relative;
}

/* 外圈进度环 SVG */
.progress-ring {
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  transform: rotate(-90deg); /* 让进度从 12 点开始 */
  pointer-events: none;
}
.progress-ring .ring-bg {
  fill: none;
  stroke: rgba(201,184,138,0.06);
  stroke-width: 1;
}
.progress-ring .ring-fg {
  fill: none;
  stroke: var(--accent);
  stroke-width: 1.5;
  stroke-linecap: round;
  filter: drop-shadow(0 0 3px rgba(201,184,138,0.4));
  will-change: stroke-dashoffset;
  /* dashoffset 由 JS 用 CSS transition 动起来 */
  transition: stroke-dashoffset linear;
}

/* 呼吸圆圈 */
.circle {
  width: 120px; height: 120px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%,
              rgba(201,184,138,0.22) 0%,
              rgba(201,184,138,0.08) 40%,
              rgba(201,184,138,0.02) 70%,
              transparent 100%);
  box-shadow: 0 0 60px rgba(201,184,138,0.1),
              inset 0 0 40px rgba(201,184,138,0.08);
  will-change: transform;
  transform: scale(1);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

/* 圆心数字计数 */
.count {
  font-family: "Didot", "Bodoni 72", "Playfair Display", Georgia, serif;
  font-size: 42px;
  font-weight: 300;
  color: var(--fg);
  opacity: 0;
  letter-spacing: 0;
  font-feature-settings: "lnum" 1;
  will-change: opacity, transform;
  transition: opacity 0.25s ease, transform 0.25s ease;
  transform: scale(0.9);
  /* 反向 scale 抵消父圆缩放(让数字相对稳定) */
}
.count.visible {
  opacity: 0.85;
  transform: scale(1);
}

.remaining {
  font-size: 13px;
  color: var(--fg-mute);
  letter-spacing: 0.3em;
  min-height: 20px;
}

/* ============== 完成界面 ============== */
#done {
  align-items: center; justify-content: center;
  background: #06080c;
  cursor: pointer;
  opacity: 0;
  transition: opacity 1.8s ease;
  overflow-y: auto;
}
#done.visible { opacity: 1; }

.done-inner {
  max-width: 640px;
  padding: 80px 44px 120px;
  text-align: center;
  margin: auto;
}
.quote-text {
  font-size: 22px;
  line-height: 2.2;
  letter-spacing: 0.12em;
  color: var(--fg);
  font-weight: 300;
  white-space: pre-line;
}
.quote-text.long {
  font-size: 16px;
  line-height: 1.9;
  letter-spacing: 0.08em;
}
.quote-source {
  margin-top: 40px;
  font-size: 13px;
  color: var(--fg-mute);
  letter-spacing: 0.25em;
  font-style: italic;
}
.done-hint {
  position: absolute;
  bottom: calc(env(safe-area-inset-bottom) + 32px);
  left: 0; right: 0;
  text-align: center;
  font-size: 11px;
  color: var(--fg-mute);
  letter-spacing: 0.4em;
  opacity: 0;
  animation: hint-fade 3s ease 4s forwards;
}
@keyframes hint-fade {
  to { opacity: 0.5; }
}

/* ============== 设置 ============== */
#settings {
  background: var(--bg-2);
  overflow-y: auto;
}
.settings-inner {
  max-width: 480px;
  margin: 0 auto;
  padding: 80px 32px 60px;
}
.settings-inner h2 {
  font-size: 22px;
  font-weight: 300;
  letter-spacing: 0.5em; text-indent: 0.5em;
  color: var(--fg);
  margin: 0 0 48px;
  text-align: center;
}
.settings-inner section {
  margin-bottom: 44px;
  padding-bottom: 36px;
  border-bottom: 1px solid var(--line);
}
.settings-inner section:last-of-type { border-bottom: none; }

.field-label {
  display: block;
  font-size: 13px;
  color: var(--fg-dim);
  letter-spacing: 0.3em;
  margin-bottom: 20px;
}

.preset-row, .bg-row {
  display: flex; flex-wrap: wrap; gap: 10px;
  margin-bottom: 20px;
}
.preset, .bg-btn {
  background: transparent;
  border: 1px solid var(--line);
  color: var(--fg-dim);
  font-family: var(--font-serif);
  font-size: 14px;
  letter-spacing: 0.15em;
  padding: 10px 18px;
  cursor: pointer;
  transition: all 0.3s ease;
}
.preset.active, .bg-btn.active {
  border-color: var(--accent-dim);
  color: var(--accent);
  background: rgba(201,184,138,0.04);
}
.preset:hover, .bg-btn:hover {
  color: var(--fg);
}

.custom-row {
  display: flex; align-items: center; gap: 14px;
  margin-top: 14px;
  font-size: 13px;
  color: var(--fg-dim);
}
.custom-row input[type=range] {
  flex: 1;
  accent-color: var(--accent);
}
.toggle-row {
  font-size: 14px;
  color: var(--fg-dim);
  margin: 6px 0 4px;
}
.toggle-row input { margin-right: 8px; accent-color: var(--accent); }

.back-btn-large {
  display: block;
  margin: 60px auto 0;
  width: 220px;
  padding: 18px 0;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--fg);
  font-family: var(--font-serif);
  font-size: 16px;
  letter-spacing: 0.4em;
  text-indent: 0.4em;
  cursor: pointer;
  transition: all 0.4s ease;
}
.back-btn-large:hover {
  border-color: var(--accent-dim);
  color: var(--accent);
  background: rgba(201,184,138,0.03);
}

.version-line {
  margin-top: 40px;
  text-align: center;
  font-size: 11px;
  color: var(--fg-mute);
  letter-spacing: 0.3em;
}

/* ===== input[type=range] 柔化 ===== */
input[type=range] {
  -webkit-appearance: none;
  height: 2px;
  background: var(--line);
  border-radius: 2px;
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
}