:root {
  --bg: #FAFAF9;
  --bg-alt: #F5F5F4;
  --surface: #FFFFFF;
  --border: #E7E5E4;
  --border-strong: #D6D3D1;
  --text: #1E293B;
  --text-secondary: #52525B;
  --text-muted: #71717A;
  --primary: #4F46E5;
  --primary-hover: #4338CA;
  --primary-light: rgba(79, 70, 229, 0.08);
  --secondary: #F97316;
  --accent: #EC4899;
  --success: #059669;
  --radius: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', 'Noto Sans SC', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.toast {
  position: fixed; top: 24px; right: 24px;
  background: var(--text); color: var(--bg);
  padding: 10px 18px; border-radius: 100px;
  font-size: 14px; font-weight: 500;
  display: flex; align-items: center; gap: 8px;
  z-index: 1000;
  transform: translateX(calc(100% + 40px));
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}
.toast.show { transform: translateX(0); }
.toast-dot { width: 8px; height: 8px; background: var(--success); border-radius: 50%; }

.page { max-width: 960px; margin: 0 auto; padding: 0 32px; }

#header.scrolled {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.06);
}

.pomodoro-section { padding: 16px 0 32px; display: flex; flex-direction: column; align-items: center; }

.pomodoro-mode-tabs {
  display: flex; gap: 4px;
  background: var(--bg-alt); border: 1px solid var(--border);
  border-radius: 100px; padding: 3px; margin-bottom: 32px;
}
.pomo-mode-btn {
  padding: 8px 20px; background: transparent; border: none;
  border-radius: 100px;
  font-family: inherit; font-size: 13px; font-weight: 500;
  color: var(--text-muted); cursor: pointer;
  transition: all 0.15s ease;
}
.pomo-mode-btn.active {
  background: var(--surface); color: var(--text);
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}

.pomodoro-ring {
  position: relative;
  width: 240px; height: 240px;
  margin-bottom: 24px;
}
.pomodoro-svg {
  width: 100%; height: 100%;
}
.pomodoro-progress {
  transition: stroke-dashoffset 0.3s linear;
}

.pomodoro-timer-text {
  position: absolute; inset: 0;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
}
.pomodoro-time {
  font-size: 48px; font-weight: 700;
  color: var(--text);
  font-family: 'DM Serif Display', Georgia, serif;
}
.pomodoro-status {
  font-size: 14px; color: var(--text-muted);
  margin-top: 4px;
}

.pomodoro-controls {
  display: flex; gap: 12px; margin-bottom: 24px;
}
.btn-pomo-main {
  padding: 14px 48px;
  background: #EF4444; color: white;
  border: none; border-radius: 100px;
  font-family: inherit; font-size: 16px; font-weight: 600;
  cursor: pointer; transition: all 0.15s ease;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.btn-pomo-main:hover { background: #DC2626; box-shadow: 0 4px 12px rgba(0,0,0,0.10); }
.btn-pomo-main.paused { background: var(--primary); }
.btn-pomo-reset {
  padding: 14px 24px;
  background: transparent; border: 1px solid var(--border);
  border-radius: 100px;
  font-family: inherit; font-size: 14px; font-weight: 600;
  color: var(--text-secondary); cursor: pointer;
  transition: all 0.15s ease;
}
.btn-pomo-reset:hover { border-color: var(--primary); color: var(--primary); }

.pomodoro-stats {
  display: flex; gap: 16px; margin-bottom: 24px;
}
.pomo-stat-box {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 12px 24px;
  text-align: center; box-shadow: var(--shadow-sm);
}
.pomo-stat-num {
  display: block; font-size: 28px; font-weight: 700; color: var(--text);
}
.pomo-stat-alt {
  font-size: 11px; font-weight: 600; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 0.06em;
}

.pomodoro-settings {
  width: 100%; max-width: 480px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 20px;
  box-shadow: var(--shadow-sm);
}
.pomo-settings-title {
  font-size: 14px; font-weight: 600; color: var(--text);
  margin-bottom: 12px;
}
.pomo-settings-row {
  display: flex; gap: 12px;
}
.pomo-settings-row div {
  flex: 1;
}
.pomo-settings-row label {
  display: block; font-size: 12px; font-weight: 500;
  color: var(--text-muted); margin-bottom: 4px;
}
.pomo-settings-row input {
  width: 100%; padding: 8px 10px; text-align: center;
  background: var(--bg-alt); border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit; font-size: 14px; color: var(--text);
  outline: none;
}
.pomo-settings-row input:focus { border-color: var(--primary); }

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: #f1f5f9; }
::-webkit-scrollbar-thumb { background: #A5B4FC; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #4F46E5; }
::selection { background: rgba(79, 70, 229, 0.2); color: #1E293B; }

.guide-section {
  margin-top: 16px; margin-bottom: 64px;
  background: #ffffff; border: 1px solid var(--border); border-radius: 12px; overflow: hidden;
}
.guide-toggle {
  display: flex; align-items: center; justify-content: space-between;
  width: 100%; padding: 14px 20px; background: none; border: none; cursor: pointer; transition: background 0.15s ease;
}
.guide-toggle:hover { background: var(--bg-alt); }
.guide-toggle-title { display: flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 600; color: #1E293B; }
.guide-toggle.open .toggle-arrow { transform: rotate(180deg); }
.toggle-arrow { transition: transform 0.2s ease; color: var(--text-muted); }
.guide-list { padding: 0 20px 20px; }
.guide-list.hidden { display: none; }
.guide-item { padding: 16px 0; border-top: 1px solid var(--border); }
.guide-item:first-child { border-top: 1px solid var(--border); }
.guide-item-title { font-size: 14px; font-weight: 600; color: #1E293B; margin-bottom: 6px; }
.guide-item-body { font-size: 13px; color: var(--text-secondary); line-height: 1.8; }

@media (max-width: 768px) {
  .page { padding: 0 16px; }
  .pomodoro-ring { width: 200px; height: 200px; }
  .pomodoro-time { font-size: 36px; }
  .pomo-settings-row { flex-direction: column; }
}