/* ============================================================
   CSS Custom Properties — Light / Dark Themes
   ============================================================ */
:root,
[data-theme="light"] {
  --gradient-bg: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  --color-surface: rgba(255, 255, 255, 0.75);
  --color-surface-alt: rgba(255, 255, 255, 0.5);
  --color-surface-input: rgba(255, 255, 255, 0.6);
  --color-border: rgba(255, 255, 255, 0.4);
  --color-text: #1e1b4b;
  --color-text-muted: #6b7280;
  --color-text-on-gradient: #ffffff;
  --color-primary: #7c3aed;
  --color-primary-hover: #6d28d9;
  --color-primary-text: #ffffff;
  --color-secondary: #ec4899;
  --color-secondary-hover: #db2777;
  --color-danger: #ef4444;
  --color-danger-hover: #dc2626;
  --color-success: #10b981;
  --color-warning-bg: rgba(254, 243, 199, 0.9);
  --color-warning-border: #f59e0b;
  --color-warning-text: #92400e;
  --color-task-done: #a78bfa;
  --shadow-card: 0 8px 32px rgba(124, 58, 237, 0.15);
  --shadow-btn: 0 4px 15px rgba(124, 58, 237, 0.3);
  --shadow-btn-danger: 0 4px 15px rgba(239, 68, 68, 0.3);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-pill: 50px;
  --blur: blur(12px);
  --transition: 0.2s ease;
}

[data-theme="dark"] {
  --gradient-bg: linear-gradient(135deg, #0f0c29 0%, #302b63 50%, #24243e 100%);
  --color-surface: rgba(30, 27, 75, 0.7);
  --color-surface-alt: rgba(49, 46, 129, 0.5);
  --color-surface-input: rgba(49, 46, 129, 0.6);
  --color-border: rgba(139, 92, 246, 0.25);
  --color-text: #ede9fe;
  --color-text-muted: #a78bfa;
  --color-text-on-gradient: #ffffff;
  --color-primary: #8b5cf6;
  --color-primary-hover: #7c3aed;
  --color-primary-text: #ffffff;
  --color-secondary: #f472b6;
  --color-secondary-hover: #ec4899;
  --color-danger: #f87171;
  --color-danger-hover: #ef4444;
  --color-success: #34d399;
  --color-warning-bg: rgba(69, 26, 3, 0.9);
  --color-warning-border: #d97706;
  --color-warning-text: #fde68a;
  --color-task-done: #6d28d9;
  --shadow-card: 0 8px 32px rgba(139, 92, 246, 0.2);
  --shadow-btn: 0 4px 15px rgba(139, 92, 246, 0.4);
  --shadow-btn-danger: 0 4px 15px rgba(248, 113, 113, 0.3);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-pill: 50px;
  --blur: blur(12px);
  --transition: 0.2s ease;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--gradient-bg);
  background-attachment: fixed;
  color: var(--color-text);
  line-height: 1.5;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

.hidden { display: none !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;
}

/* ============================================================
   Warning Banner
   ============================================================ */
.warning-banner {
  background-color: var(--color-warning-bg);
  border-bottom: 2px solid var(--color-warning-border);
  color: var(--color-warning-text);
  padding: 0.5rem 1rem;
  text-align: center;
  font-size: 0.875rem;
  backdrop-filter: var(--blur);
}

/* ============================================================
   Header
   ============================================================ */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  padding: 1.25rem 2rem;
  background: var(--color-surface);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-card);
  position: sticky;
  top: 0;
  z-index: 10;
}

.clock-section { display: flex; flex-direction: column; gap: 0.125rem; }

.clock {
  font-size: 2.25rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.date-display {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

.greeting-section {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex: 1;
  min-width: 200px;
}

.greeting {
  font-size: 1.375rem;
  font-weight: 700;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.name-form {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
}

.name-input {
  flex: 1;
  min-width: 120px;
  padding: 0.5rem 0.875rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-surface-input);
  backdrop-filter: var(--blur);
  color: var(--color-text);
  font-size: 0.875rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.name-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.15);
}

.header-actions { display: flex; align-items: center; gap: 0.5rem; }

/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  padding: 0.55rem 1.25rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-surface-alt);
  backdrop-filter: var(--blur);
  color: var(--color-text);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  letter-spacing: 0.01em;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  border-color: var(--color-primary);
}

.btn:active { transform: translateY(0); }

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Primary — gradient fill */
.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-color: transparent;
  color: #ffffff;
  box-shadow: var(--shadow-btn);
}
.btn-primary:hover {
  background: linear-gradient(135deg, var(--color-primary-hover), var(--color-secondary-hover));
  box-shadow: 0 6px 20px rgba(124, 58, 237, 0.45);
  border-color: transparent;
}

.btn-sm { padding: 0.35rem 0.875rem; font-size: 0.8125rem; }

.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--color-text-muted);
}
.btn-ghost:hover {
  background: var(--color-surface-alt);
  border-color: var(--color-border);
  color: var(--color-text);
  box-shadow: none;
}

/* Icon button — theme toggle */
.btn-icon {
  padding: 0.5rem;
  font-size: 1.25rem;
  background: var(--color-surface-alt);
  border: 1.5px solid var(--color-border);
  border-radius: 50%;
  width: 2.5rem;
  height: 2.5rem;
  transition: all var(--transition);
}
.btn-icon:hover {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  border-color: transparent;
  transform: rotate(20deg) scale(1.1);
  box-shadow: var(--shadow-btn);
}

/* Danger */
.btn-danger {
  background: transparent;
  border-color: transparent;
  color: var(--color-danger);
  font-size: 0.8rem;
}
.btn-danger:hover {
  background: linear-gradient(135deg, var(--color-danger), #f97316);
  color: #fff;
  border-color: transparent;
  box-shadow: var(--shadow-btn-danger);
}

/* ============================================================
   Main Grid
   ============================================================ */
.main-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  padding: 1.75rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

/* ============================================================
   Cards — glassmorphism
   ============================================================ */
.card {
  background: var(--color-surface);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(124, 58, 237, 0.2);
}

.card-title {
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ============================================================
   Timer
   ============================================================ */
.timer-display {
  font-size: 4rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  text-align: center;
  letter-spacing: 0.04em;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  padding: 0.5rem 0;
}

.timer-controls {
  display: flex;
  gap: 0.625rem;
  justify-content: center;
  flex-wrap: wrap;
}

.duration-form { display: flex; flex-direction: column; gap: 0.5rem; }

/* ============================================================
   Forms & Inputs
   ============================================================ */
.form-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.input-row { display: flex; gap: 0.5rem; align-items: center; }

.input-field {
  flex: 1;
  padding: 0.5rem 0.875rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-surface-input);
  backdrop-filter: var(--blur);
  color: var(--color-text);
  font-size: 0.875rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.input-field:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.15);
}

/* number input arrows */
input[type="number"] { -moz-appearance: textfield; }
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; }

.select-field {
  padding: 0.5rem 0.875rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-surface-input);
  backdrop-filter: var(--blur);
  color: var(--color-text);
  font-size: 0.875rem;
  cursor: pointer;
  font-weight: 500;
  transition: border-color var(--transition);
}
.select-field:focus {
  outline: none;
  border-color: var(--color-primary);
}

.validation-msg {
  font-size: 0.8125rem;
  color: var(--color-danger);
  font-weight: 500;
  padding-left: 0.25rem;
}

/* ============================================================
   Tasks
   ============================================================ */
.task-form { display: flex; flex-direction: column; gap: 0.5rem; }

.sort-row { display: flex; align-items: center; gap: 0.625rem; }

.task-list { list-style: none; display: flex; flex-direction: column; gap: 0.625rem; }

.task-item {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  padding: 0.625rem 0.875rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface-alt);
  backdrop-filter: var(--blur);
  transition: all var(--transition);
}

.task-item:hover {
  border-color: var(--color-primary);
  box-shadow: 0 2px 12px rgba(124, 58, 237, 0.12);
}

.task-item.completed {
  opacity: 0.65;
}

.task-item.completed .task-title {
  text-decoration: line-through;
  color: var(--color-task-done);
}

.task-checkbox {
  width: 1.1rem;
  height: 1.1rem;
  cursor: pointer;
  accent-color: var(--color-primary);
  flex-shrink: 0;
}

.task-title { flex: 1; font-size: 0.9375rem; word-break: break-word; font-weight: 500; }

.task-edit-input {
  flex: 1;
  padding: 0.25rem 0.625rem;
  border: 1.5px solid var(--color-primary);
  border-radius: var(--radius-sm);
  background: var(--color-surface-input);
  color: var(--color-text);
  font-size: 0.9375rem;
}

.task-actions { display: flex; gap: 0.25rem; flex-shrink: 0; }

/* ============================================================
   Links
   ============================================================ */
.link-form { display: flex; flex-direction: column; gap: 0.5rem; }

.link-list { list-style: none; display: flex; flex-direction: column; gap: 0.625rem; }

.link-item { display: flex; align-items: center; gap: 0.5rem; }

.link-btn {
  flex: 1;
  padding: 0.5rem 1rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-surface-alt);
  backdrop-filter: var(--blur);
  color: var(--color-primary);
  font-size: 0.875rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: all var(--transition);
}
.link-btn:hover {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: #ffffff;
  border-color: transparent;
  box-shadow: var(--shadow-btn);
  transform: translateY(-1px);
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 640px) {
  .header { padding: 1rem; flex-direction: column; align-items: flex-start; }
  .clock { font-size: 1.75rem; }
  .timer-display { font-size: 3rem; }
  .main-grid { padding: 1rem; gap: 1rem; }
}