/* === Design Tokens === */
:root {
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

/* Light mode */
:root,
[data-theme='light'] {
  --color-bg: #f7f6f2;
  --color-surface: #ffffff;
  --color-surface-2: #f3f0ec;
  --color-surface-hover: #edeae5;
  --color-border: #e0ddd7;
  --color-divider: #dcd9d5;
  --color-text: #28251d;
  --color-text-muted: #7a7974;
  --color-text-faint: #bab9b4;
  --color-primary: #01696f;
  --color-primary-hover: #0c4e54;
  --color-primary-text: #ffffff;
  --color-danger: #c0392b;
  --color-danger-hover: #a93226;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.06), 0 1px 3px rgba(0,0,0,0.04);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.1);
}

/* Dark mode */
[data-theme='dark'] {
  --color-bg: #1e1f26;
  --color-surface: #262833;
  --color-surface-2: #2c2e3b;
  --color-surface-hover: #34374a;
  --color-border: #3d4055;
  --color-divider: #353749;
  --color-text: #d4d6e0;
  --color-text-muted: #8b8ea0;
  --color-text-faint: #65697e;
  --color-primary: #5ba9b8;
  --color-primary-hover: #72bcc9;
  --color-primary-text: #1e1f26;
  --color-danger: #e06650;
  --color-danger-hover: #f07860;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.3), 0 1px 3px rgba(0,0,0,0.2);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
}

/* === Reset === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
}

a, button, input { transition: color var(--transition), background var(--transition), border-color var(--transition), box-shadow var(--transition), opacity var(--transition); }

button { cursor: pointer; background: none; border: none; font: inherit; color: inherit; }
input { font: inherit; color: inherit; }

::selection { background: color-mix(in srgb, var(--color-primary) 25%, transparent); }

:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 3px; border-radius: var(--radius-sm); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* === Header === */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-primary);
  flex-shrink: 0;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--text-lg);
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.search-bar {
  flex: 1;
  max-width: 400px;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
}

.search-bar:focus-within {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 15%, transparent);
}

.search-bar input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  font-size: var(--text-sm);
  color: var(--color-text);
}

.search-bar input::placeholder { color: var(--color-text-faint); }

.search-submit {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px; height: 28px;
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
  flex-shrink: 0;
  margin-right: -4px;
}

.search-submit:hover {
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 12%, transparent);
}

/* === Clock === */
.header-clock {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  line-height: 1.3;
  flex-shrink: 0;
  margin-left: auto;
}

.clock-time {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

.clock-date {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 400;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px; height: 38px;
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.icon-btn:hover { color: var(--color-text); background: var(--color-surface-hover); }

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-primary-text);
  font-weight: 700;
}

.btn-primary:hover { background: var(--color-primary-hover); }

.btn-ghost {
  background: transparent;
  color: var(--color-text-muted);
  border-color: var(--color-border);
}

.btn-ghost:hover { color: var(--color-text); background: var(--color-surface-hover); }

.btn-danger {
  background: var(--color-danger);
  color: #fff;
  font-weight: 600;
}

.btn-danger:hover { background: var(--color-danger-hover); }

/* === Main Board === */
.main {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-8) var(--space-6) var(--space-16);
}

.board {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 250px));
  gap: var(--space-5);
  align-items: start;
}

/* === Group Card === */
.group-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.group-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-4) var(--space-3);
  border-bottom: 1px solid var(--color-divider);
}

.group-title-area {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-width: 0;
}

.group-icon {
  width: 8px; height: 8px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  flex-shrink: 0;
}

.group-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.group-count {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-weight: 400;
  flex-shrink: 0;
}

.group-actions {
  display: flex;
  gap: var(--space-1);
  opacity: 0;
  transition: opacity var(--transition);
}

.group-card:hover .group-actions { opacity: 1; }

.group-action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px; height: 28px;
  border-radius: var(--radius-sm);
  color: var(--color-text-faint);
}

.group-action-btn:hover { color: var(--color-text); background: var(--color-surface-hover); }

.group-action-btn.danger:hover { color: var(--color-danger); }

/* === Links List === */
.links-list {
  list-style: none;
  padding: var(--space-2);
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.link-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-md);
  position: relative;
}

.link-item:hover { background: var(--color-surface-2); }

.link-favicon {
  width: 20px; height: 20px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  background: var(--color-surface-hover);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 700;
  color: var(--color-text-muted);
  overflow: hidden;
}

.link-favicon img {
  width: 100%; height: 100%;
  object-fit: contain;
}

.link-content {
  flex: 1;
  min-width: 0;
}

.link-title {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  text-decoration: none;
  display: block;
}

.link-title:hover { color: var(--color-primary); }

.link-url {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  display: none;
}

.link-actions {
  position: absolute;
  right: var(--space-2);
  display: flex;
  gap: var(--space-1);
  opacity: 0;
  transition: opacity var(--transition);
  pointer-events: none;
  background: var(--color-surface-2);
  border-radius: var(--radius-sm);
  padding: 0 var(--space-1);
}

.link-item:hover .link-actions {
  opacity: 1;
  pointer-events: auto;
}

.link-action-btn.move {
  color: var(--color-text-faint);
}

.link-action-btn:disabled {
  cursor: default;
}

.link-action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 26px; height: 26px;
  border-radius: var(--radius-sm);
  color: var(--color-text-faint);
}

.link-action-btn:hover { color: var(--color-text); background: var(--color-surface-hover); }
.link-action-btn.danger:hover { color: var(--color-danger); }

/* === Add link button === */
.add-link-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3);
  margin: 0 var(--space-2) var(--space-2);
  border-radius: var(--radius-md);
  border: 1px dashed var(--color-border);
  color: var(--color-text-faint);
  font-size: var(--text-sm);
  font-weight: 500;
}

.add-link-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 5%, transparent);
}

/* === Empty state === */
.empty-state[hidden] { display: none; }

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  padding: var(--space-16) var(--space-4);
  text-align: center;
  color: var(--color-text-faint);
}

.empty-state h2 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
}

.empty-state p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
}

/* === Empty group === */
.group-empty {
  padding: var(--space-4) var(--space-3);
  text-align: center;
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* === Modal === */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  animation: fadeIn 150ms ease;
}

.modal-overlay[hidden] { display: none; }

@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.modal {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--space-6);
  width: 100%;
  max-width: 420px;
  animation: slideUp 200ms cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-sm { max-width: 360px; }

@keyframes slideUp { from { transform: translateY(16px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }

.modal-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-lg);
  margin-bottom: var(--space-4);
}

.modal-text {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.modal-hint {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-1);
  min-height: 1em;
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.field-label {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
}

.field input, .field-select {
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--color-text);
  outline: none;
}

.field-select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='14' viewBox='0 0 24 24' fill='none' stroke='%23888' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2.5rem;
}

.field input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 15%, transparent);
}

.field input::placeholder, .field-select::placeholder { color: var(--color-text-faint); }

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-2);
  margin-top: var(--space-2);
}

/* === Responsive === */
@media (max-width: 640px) {
  .header-inner {
    padding: var(--space-3) var(--space-4);
    flex-wrap: wrap;
  }
  .brand-name { display: none; }
  .search-bar { order: 3; width: 100%; flex-basis: 100%; max-width: none; }
  .main { padding: var(--space-4) var(--space-4) var(--space-12); }
  .board { grid-template-columns: 1fr; }
  .header-clock { order: 2; margin-left: 0; }
  .header-actions { order: 1; margin-left: auto; }
  .group-actions { opacity: 1; }
  .link-actions { opacity: 1; }
}