/* ============================================================
   Soil Engineering Tools - shared stylesheet
   ============================================================ */
:root {
  --primary: #0f4c81;
  --primary-dark: #0a355c;
  --primary-light: #e8f0f8;
  --accent: #e07b39;
  --accent-dark: #c96a2b;
  --success: #2e8b57;
  --danger: #c0392b;
  --bg: #f4f6f9;
  --card: #ffffff;
  --text: #1f2d3d;
  --text-muted: #5b6b7c;
  --border: #dde3ea;
  --shadow: 0 2px 8px rgba(15, 76, 129, 0.08);
  --radius: 10px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Noto Sans JP", "Noto Sans KR", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- Header (brand top-left, actions + selects top-right) ---------- */
.site-header {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  color: #fff;
  padding: 12px 20px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: #fff;
}
.brand-logo {
  width: 40px;
  height: 40px;
  border-radius: 9px;
  background: linear-gradient(135deg, #ffb347, #e07b39);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 18px;
  color: #fff;
  flex: 0 0 auto;
}
.brand-name { font-size: 18px; font-weight: 700; line-height: 1.2; }
.brand-tag { font-size: 11px; opacity: 0.85; }

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.header-actions .btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid rgba(255,255,255,0.35);
  color: #fff;
  background: rgba(255,255,255,0.12);
  transition: background .2s;
  cursor: pointer;
}
.header-actions .btn:hover { background: rgba(255,255,255,0.24); }
.header-actions .btn.btn-home { background: var(--accent); border-color: var(--accent); }
.header-actions .btn.btn-home:hover { background: var(--accent-dark); }
.header-actions .btn svg { width: 15px; height: 15px; flex: 0 0 auto; }
.header-actions .ctl-divider { width: 1px; height: 22px; background: rgba(255,255,255,0.3); margin: 0 4px; }
.header-actions select {
  padding: 7px 10px;
  border-radius: 6px;
  border: 1px solid rgba(255,255,255,0.4);
  background: rgba(255,255,255,0.14);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  outline: none;
}
.header-actions select option { color: #1f2d3d; background: #fff; }
.header-actions label { font-size: 12px; opacity: 0.9; white-space: nowrap; }

/* ---------- Nav (Windows-style menu bar) ---------- */
.site-nav {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: stretch;
  gap: 0;
  overflow-x: auto;
  padding: 0 20px;
}
.menu-link, .menu-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 12px 15px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  background: none;
  border: none;
  cursor: pointer;
  white-space: nowrap;
  border-bottom: 3px solid transparent;
  transition: color .2s, border-color .2s, background .2s;
  font-family: inherit;
}
.menu-link:hover, .menu-btn:hover { color: var(--primary); background: var(--primary-light); }
.menu-link.active, .menu-item.active > .menu-btn { color: var(--primary); border-bottom-color: var(--primary); }
.menu-item { position: relative; flex: 0 0 auto; }
.menu-item .caret { width: 12px; height: 12px; margin-left: 2px; opacity: 0.55; flex: 0 0 auto; }
.menu-item.open > .menu-btn { color: var(--primary); background: var(--primary-light); border-bottom-color: var(--primary); }
.menu-item.open .caret { transform: rotate(180deg); }
.menu-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 280px;
  max-height: 70vh;
  overflow-y: auto;
  background: #fff;
  border: 1px solid var(--border);
  border-top: 3px solid var(--primary);
  border-radius: 0 0 8px 8px;
  box-shadow: 0 12px 30px rgba(15, 76, 129, 0.18);
  padding: 6px;
  display: none;
  z-index: 300;
}
.menu-item.open .menu-dropdown { display: block; }
.site-nav .menu-dropdown a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: none;
}
.site-nav .menu-dropdown a svg { width: 16px; height: 16px; flex: 0 0 auto; color: var(--primary); }
.site-nav .menu-dropdown a:hover { background: var(--primary-light); color: var(--primary); }
.site-nav .menu-dropdown a.active { background: var(--primary-light); color: var(--primary); font-weight: 700; }

/* ---------- Layout ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 20px;
  width: 100%;
  flex: 1;
}
.page-head { margin-bottom: 20px; }
.page-title { font-size: 26px; font-weight: 700; color: var(--primary-dark); margin-bottom: 6px; }
.page-desc { color: var(--text-muted); font-size: 14.5px; max-width: 860px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  margin-bottom: 20px;
}
.card-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.card-title .num {
  width: 24px; height: 24px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 13px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
}

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 900px) { .grid-2, .grid-3 { grid-template-columns: 1fr; } }

/* ---------- Forms ---------- */
.form-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.form-row label { font-size: 13.5px; font-weight: 600; min-width: 200px; color: var(--text); }
.form-row input[type="number"], .form-row input[type="text"], .form-row select {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  width: 140px;
  background: #fff;
  color: var(--text);
  outline: none;
  transition: border-color .2s;
}
.form-row input:focus, .form-row select:focus { border-color: var(--primary); }
.form-row .unit { font-size: 12.5px; color: var(--text-muted); }

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 12px 20px;
}
.form-grid .field { display: flex; flex-direction: column; gap: 4px; }
.form-grid .field label { font-size: 13px; font-weight: 600; color: var(--text); }
.form-grid .field input, .form-grid .field select {
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  background: #fff;
  outline: none;
}
.form-grid .field input:focus, .form-grid .field select:focus { border-color: var(--primary); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 7px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: background .2s, transform .1s;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: var(--accent-dark); }
.btn-outline { background: #fff; color: var(--primary); border: 1.5px solid var(--primary); }
.btn-outline:hover { background: var(--primary-light); }
.btn-sm { padding: 6px 12px; font-size: 12.5px; }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 6px; }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; }
table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
  min-width: 520px;
}
table.data th, table.data td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  text-align: center;
}
table.data th {
  background: var(--primary-light);
  color: var(--primary-dark);
  font-weight: 700;
  font-size: 12.5px;
}
table.data td input {
  width: 90px;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 5px;
  font-size: 13.5px;
  text-align: center;
  outline: none;
}
table.data td input:focus { border-color: var(--primary); }
table.data tbody tr:nth-child(even) { background: #fafbfd; }
table.data .row-head { background: var(--primary-light); font-weight: 700; color: var(--primary-dark); }
table.data td.result-cell { font-weight: 700; color: var(--primary-dark); background: #f0f6fc; }

/* ---------- Results ---------- */
.result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
}
.result-box {
  background: var(--primary-light);
  border: 1px solid #c9dcee;
  border-radius: 8px;
  padding: 14px;
  text-align: center;
}
.result-box .label { font-size: 12px; color: var(--text-muted); font-weight: 600; margin-bottom: 4px; }
.result-box .value { font-size: 22px; font-weight: 800; color: var(--primary-dark); }
.result-box .sub { font-size: 11.5px; color: var(--text-muted); margin-top: 2px; }
.result-box.success { background: #eaf6ee; border-color: #b7e0c5; }
.result-box.success .value { color: var(--success); }
.result-box.fail { background: #fdecea; border-color: #f5c6c0; }
.result-box.fail .value { color: var(--danger); }

/* ---------- Charts ---------- */
.chart-box {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
}
.chart-box canvas { width: 100%; height: auto; display: block; }
.chart-title { font-size: 13px; font-weight: 700; color: var(--text-muted); text-align: center; margin-bottom: 8px; }

/* ---------- Home page ---------- */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  border-radius: var(--radius);
  padding: 16px 28px;
  margin-bottom: 24px;
}
.hero .badges { display: flex; gap: 8px; flex-wrap: wrap; }
.hero .badge {
  background: rgba(255,255,255,0.16);
  border: 1px solid rgba(255,255,255,0.3);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 18px;
}
.tool-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
  text-decoration: none;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform .15s, box-shadow .2s, border-color .2s;
}
.tool-card:hover { transform: translateY(-3px); box-shadow: 0 6px 18px rgba(15,76,129,0.15); border-color: var(--primary); }
.tool-card .icon {
  width: 46px; height: 46px;
  border-radius: 10px;
  background: var(--primary-light);
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
}
.tool-card h3 { font-size: 16.5px; color: var(--primary-dark); }
.tool-card p { font-size: 13.5px; color: var(--text-muted); flex: 1; }
.tool-card .go { font-size: 13px; font-weight: 700; color: var(--accent); }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--primary-dark);
  color: rgba(255,255,255,0.85);
  padding: 22px 20px;
  margin-top: auto;
  font-size: 13px;
}
.footer-inner { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.footer-inner a { color: #ffd9b3; text-decoration: none; }
.footer-inner a:hover { text-decoration: underline; }

/* ---------- Misc ---------- */
.note-box {
  background: #fff8ec;
  border: 1px solid #f0d9b0;
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  padding: 12px 14px;
  font-size: 13px;
  color: #6b4f2a;
  margin-bottom: 16px;
}
.error-box {
  background: #fdecea;
  border: 1px solid #f5c6c0;
  border-left: 4px solid var(--danger);
  border-radius: 6px;
  padding: 12px 14px;
  font-size: 13.5px;
  color: var(--danger);
  margin-bottom: 16px;
  display: none;
}
.error-box.show { display: block; }
.hidden { display: none !important; }
.mt-16 { margin-top: 16px; }
.mb-16 { margin-bottom: 16px; }
.text-muted { color: var(--text-muted); }
.flex-between { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.section-label { font-size: 13px; font-weight: 700; color: var(--primary-dark); margin: 16px 0 8px; }

/* ---------- Flash note toast ---------- */
.flash-note {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%) translateY(20px);
  background: var(--primary-dark);
  color: #fff;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 13.5px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.25);
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s, transform .25s;
  z-index: 1000;
}
.flash-note.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media print {
  .site-header, .site-nav, .site-footer, .btn-row, .no-print { display: none !important; }
  body { background: #fff; }
  .card { box-shadow: none; border-color: #ccc; break-inside: avoid; }
}