/* === Theme tokens === */

:root,
:root[data-theme="light"],
:root[data-theme="auto"] {
  color-scheme: light;
  --bg-1: #f0fbff;
  --bg-2: #c2ecff;
  --bg-radial-1: #ffffff;
  --bg-radial-2: #ffd6e7;
  --surface: #ffffff;
  --surface-2: #f6fbff;
  --surface-3: #ebf6fb;
  --surface-glass: rgba(255, 255, 255, 0.85);
  --border: #c2ecff;
  --border-soft: #e2f1f9;
  --border-strong: #9bdcf7;
  --ink: #1f4861;
  --ink-soft: #4a7a92;
  --ink-mute: #6a8fa6;
  --primary: #4ab2dc;
  --primary-strong: #2d8fb9;
  --primary-soft: #dff5ff;
  --accent: #ff9eb5;
  --accent-strong: #e36b8e;
  --accent-soft: #ffd6e7;
  --gold: #f4c44a;
  --silver: #b8c9d4;
  --bronze: #d49a6a;
  --green-bg: #d8f5e0;
  --green-text: #3a8553;
  --orange-bg: #fde7d8;
  --orange-text: #b56730;
  --red: #e23939;
  --shadow-sm: 0 2px 8px rgba(106, 184, 219, 0.15);
  --shadow: 0 8px 24px rgba(106, 184, 219, 0.22);
  --shadow-lg: 0 16px 40px rgba(106, 184, 219, 0.28);
  --radius-sm: 12px;
  --radius: 18px;
  --radius-lg: 28px;
  --tnum: "tnum";
}

@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] {
    color-scheme: dark;
    --bg-1: #0a1828;
    --bg-2: #142a44;
    --bg-radial-1: #1a3252;
    --bg-radial-2: #2a1a3a;
    --surface: #14253a;
    --surface-2: #1a2d44;
    --surface-3: #20354f;
    --surface-glass: rgba(20, 37, 58, 0.85);
    --border: #2a4060;
    --border-soft: #1f3650;
    --border-strong: #3b5d85;
    --ink: #e5f0f9;
    --ink-soft: #b0c5d8;
    --ink-mute: #7a92ad;
    --primary: #6cc6ec;
    --primary-strong: #9bdcf7;
    --primary-soft: #1d3550;
    --accent: #ff9eb5;
    --accent-strong: #ffb8d4;
    --accent-soft: #4a2540;
    --gold: #f4c44a;
    --silver: #d0d8e0;
    --bronze: #d49a6a;
    --green-bg: #1f4030;
    --green-text: #7ad99c;
    --orange-bg: #4a2c1a;
    --orange-text: #ffb084;
    --red: #ff7575;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg-1: #0a1828;
  --bg-2: #142a44;
  --bg-radial-1: #1a3252;
  --bg-radial-2: #2a1a3a;
  --surface: #14253a;
  --surface-2: #1a2d44;
  --surface-3: #20354f;
  --surface-glass: rgba(20, 37, 58, 0.85);
  --border: #2a4060;
  --border-soft: #1f3650;
  --border-strong: #3b5d85;
  --ink: #e5f0f9;
  --ink-soft: #b0c5d8;
  --ink-mute: #7a92ad;
  --primary: #6cc6ec;
  --primary-strong: #9bdcf7;
  --primary-soft: #1d3550;
  --accent: #ff9eb5;
  --accent-strong: #ffb8d4;
  --accent-soft: #4a2540;
  --gold: #f4c44a;
  --silver: #d0d8e0;
  --bronze: #d49a6a;
  --green-bg: #1f4030;
  --green-text: #7ad99c;
  --orange-bg: #4a2c1a;
  --orange-text: #ffb084;
  --red: #ff7575;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
}

/* === Reset / base === */

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: "Hiragino Maru Gothic ProN", "Yu Gothic", "Meiryo", system-ui, sans-serif;
  background:
    radial-gradient(circle at 15% 5%, var(--bg-radial-1) 0%, transparent 38%),
    radial-gradient(circle at 85% 95%, var(--bg-radial-2) 0%, transparent 32%),
    linear-gradient(180deg, var(--bg-1) 0%, var(--bg-2) 100%);
  background-attachment: fixed;
  color: var(--ink);
  min-height: 100vh;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition: background 0.3s ease, color 0.2s ease;
}

a { color: var(--primary-strong); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; }
input, select, textarea { font-family: inherit; color: inherit; }

::selection { background: var(--primary-soft); color: var(--ink); }

/* === Background bubbles === */

.bubbles {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}
.bubble {
  position: absolute;
  background: var(--surface);
  border-radius: 50%;
  filter: blur(2px);
  opacity: 0.55;
}
.bubble.b1 { width: 180px; height: 60px; top: 12%;    left: -50px;  animation: drift 32s linear infinite; }
.bubble.b2 { width: 120px; height: 40px; top: 38%;    right: -40px; animation: drift-rev 38s linear infinite; }
.bubble.b3 { width: 220px; height: 70px; bottom: 12%; left: 10%;    animation: drift 44s linear infinite; }
.bubble.b4 { width: 90px;  height: 30px; bottom: 30%; right: 20%;   animation: drift-rev 50s linear infinite; }

:root[data-theme="dark"] .bubble { opacity: 0.10; }
@media (prefers-color-scheme: dark) {
  :root[data-theme="auto"] .bubble { opacity: 0.10; }
}

@keyframes drift     { from { transform: translateX(0); } to { transform: translateX(110vw); } }
@keyframes drift-rev { from { transform: translateX(0); } to { transform: translateX(-110vw); } }

/* === Layout primitives === */

.container {
  position: relative;
  z-index: 1;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
}

main.container { padding-top: 28px; padding-bottom: 80px; }

/* === Topbar === */

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--surface-glass);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border-soft);
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  height: 56px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
}
.brand:hover { text-decoration: none; opacity: 0.85; }
.brand-icon {
  font-size: 22px;
  line-height: 1;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-title { font-size: 15px; font-weight: 700; letter-spacing: 0.02em; }
.brand-dim { color: var(--ink-mute); font-weight: 500; }
.brand-sub { font-size: 10.5px; color: var(--accent-strong); letter-spacing: 0.1em; font-weight: 600; }

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* === Footer === */

.site-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  margin-top: 56px;
  padding: 24px 16px 32px;
  color: var(--ink-mute);
  font-size: 12px;
}
.site-footer .heart { color: var(--accent); }
.site-footer a { color: var(--primary-strong); }

/* === Animations === */

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes spin { to { transform: rotate(360deg); } }