/* styles.css */
:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --bg-color: #f3f4f6;
  --panel-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.5);
  --text-main: #111827;
  --text-muted: #6b7280;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-glass: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
  --radius-lg: 16px;
  --radius-md: 12px;
}

[data-theme="dark"] {
  --bg-color: #0f172a;
  --panel-bg: rgba(30, 41, 59, 0.85);
  --glass-border: rgba(255, 255, 255, 0.08);
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
  --shadow-glass: 0 8px 32px 0 rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] body {
  background-image: radial-gradient(circle at 15% 50%, rgba(79, 70, 229, 0.15), transparent 25%),
                    radial-gradient(circle at 85% 30%, rgba(56, 189, 248, 0.08), transparent 25%);
}
[data-theme="dark"] .toolbar {
  background: rgba(255, 255, 255, 0.03);
}
[data-theme="dark"] .date-group h3,
[data-theme="dark"] .list-header-row {
  background: rgba(255, 255, 255, 0.05);
}
[data-theme="dark"] .event-list-item:hover,
[data-theme="dark"] .event-list-item:focus-visible {
  background: rgba(255, 255, 255, 0.05);
}
[data-theme="dark"] .modal-attachments {
  background: rgba(255, 255, 255, 0.03);
}
[data-theme="dark"] .attachment-item {
  border-color: rgba(255, 255, 255, 0.1);
}
[data-theme="dark"] .attachment-item:hover {
  background: rgba(255, 255, 255, 0.08);
}
[data-theme="dark"] .token-input {
  background: rgba(255, 255, 255, 0.07);
  border-color: rgba(255, 255, 255, 0.15);
}
[data-theme="dark"] select {
  background: rgba(30, 41, 59, 0.9) !important;
  border-color: rgba(255, 255, 255, 0.15) !important;
  color: var(--text-main) !important;
}
[data-theme="dark"] .month-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}
[data-theme="dark"] .custom-checkbox {
  border-color: #64748b;
}
[data-theme="dark"] .modal-content {
  background: #1e293b;
}
[data-theme="dark"] .modal-body {
  color: #cbd5e1;
}
[data-theme="dark"] .modal-body img {
  border-radius: 4px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-color: #0f172a;
    --panel-bg: rgba(30, 41, 59, 0.85);
    --glass-border: rgba(255, 255, 255, 0.08);
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
    --shadow-glass: 0 8px 32px 0 rgba(0, 0, 0, 0.4);
  }
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  padding: 2rem;
  background-image: radial-gradient(circle at 15% 50%, rgba(79, 70, 229, 0.1), transparent 25%),
                    radial-gradient(circle at 85% 30%, rgba(56, 189, 248, 0.1), transparent 25%);
  background-attachment: fixed;
}

/* Custom Webkit Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background-color: rgba(107, 114, 128, 0.3);
  border-radius: 20px;
}
::-webkit-scrollbar-thumb:hover {
  background-color: rgba(107, 114, 128, 0.5);
}

/* Focus Visibility (A11y) */
*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.app-container {
  width: 100%;
  max-width: 100%;
  background: var(--panel-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-glass);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 80vh;
}

/* Header */
header {
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.student-badge {
  font-size: 0.875rem;
  background: var(--primary);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-weight: 500;
}

/* Auth Section */
.auth-panel {
  padding: 2rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  margin: auto;
}
.token-input {
  width: 100%;
  max-width: 400px;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--glass-border);
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  font-family: monospace;
  outline: none;
  transition: box-shadow 0.2s;
}
.token-input:focus {
  box-shadow: 0 0 0 2px var(--primary);
}
.btn {
  background: var(--primary);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}
.btn:hover { background: var(--primary-hover); }
.btn:active { transform: scale(0.98); }

/* Main Content */
.main-content {
  display: none; /* hidden until auth */
  flex-direction: column;
  flex: 1;
}

.toolbar {
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  border-bottom: 1px solid var(--glass-border);
  background: rgba(0,0,0,0.02);
}
.month-nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-weight: 600;
}
.month-btn {
  background: transparent;
  border: none;
  color: var(--text-main);
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 50%;
  transition: background 0.2s;
}
.month-btn:hover { background: rgba(0,0,0,0.05); }

.filters {
  display: flex;
  gap: 1rem;
  align-items: center;
}

/* Event List */
.event-list {
  padding: 2rem;
  overflow-y: auto;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  scroll-behavior: smooth;
}
@keyframes slideUpFade {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.date-group {
  background: var(--panel-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  animation: slideUpFade 0.4s ease-out forwards;
}
.date-group h3 {
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-main);
  background: rgba(0,0,0,0.03);
  padding: 0.75rem 1rem;
  margin: 0;
  border-bottom: 1px solid var(--glass-border);
  font-weight: 700;
}
/* List Header */
.list-header-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
  border-bottom: 2px solid var(--glass-border);
  background: rgba(0,0,0,0.03);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.header-checkbox {
  width: 24px;
  flex-shrink: 0;
}
.event-list-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--glass-border);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  background: transparent;
}
.event-list-item:last-child {
  border-bottom: none;
}
.event-list-item:hover, .event-list-item:focus-visible {
  background: rgba(0,0,0,0.02);
  transform: translateX(4px);
}
.event-list-item.completed {
  opacity: 0.6;
}
.event-list-item.completed .item-title {
  text-decoration: line-through;
  color: var(--text-muted);
}

.item-checkbox {
  flex-shrink: 0;
  display: flex;
  align-items: center;
}
.custom-checkbox {
  appearance: none;
  width: 20px;
  height: 20px;
  border: 2px solid var(--text-muted);
  border-radius: 6px;
  cursor: pointer;
  display: grid;
  place-content: center;
  transition: all 0.2s ease-in-out;
}
.custom-checkbox::before {
  content: "";
  width: 10px;
  height: 10px;
  transform: scale(0);
  transition: 120ms transform ease-in-out;
  box-shadow: inset 1em 1em var(--bg-color);
  background-color: transparent;
  transform-origin: center;
  clip-path: polygon(14% 44%, 0 65%, 50% 100%, 100% 16%, 80% 0%, 43% 62%);
}
.custom-checkbox:checked {
  background-color: var(--primary);
  border-color: var(--primary);
}
.custom-checkbox:checked::before {
  transform: scale(1);
}

/* List Item Internals (Grid Rows) */
.item-content {
  flex: 1;
  display: grid;
  grid-template-columns: 32px minmax(200px, 3fr) minmax(150px, 2fr) 200px 180px;
  align-items: center;
  gap: 1rem;
  min-width: 0;
}
.item-badge {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: grid;
  place-content: center;
  color: white;
  font-size: 0.85rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.item-title {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.item-materia, .item-time, .item-prof {
  font-size: 0.85rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
@media (max-width: 1024px) {
  .item-content {
    grid-template-columns: 40px minmax(150px, 2fr) minmax(120px, 1fr) 180px;
  }
  .item-prof { display: none; }
}
@media (max-width: 768px) {
  .list-header-row { display: none; }
  .item-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
  .item-materia, .item-time, .item-prof { display: flex; }
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  backdrop-filter: blur(4px);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 50;
  opacity: 0;
  transition: opacity 0.3s ease;
}
.modal-overlay.active { display: flex; opacity: 1; }
.modal-content {
  background: var(--bg-color);
  width: 90%;
  max-width: 600px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-glass);
  overflow: hidden;
  transform: scale(0.95);
  transition: transform 0.3s ease, max-width 0.3s ease;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
}
.modal-content.large {
  max-width: 1100px;
}
.modal-overlay.active .modal-content { transform: scale(1); }
.modal-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}
.modal-close {
  background: transparent;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-muted);
}
.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  line-height: 1.6;
}
.modal-attachments {
  padding: 1rem 1.5rem;
  background: rgba(0,0,0,0.02);
  border-top: 1px solid var(--glass-border);
}

.attachment-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem;
  background: var(--panel-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  margin-top: 0.5rem;
  cursor: pointer;
  text-decoration: none;
  color: var(--text-main);
  transition: background 0.2s;
}
.attachment-item:hover { background: rgba(0,0,0,0.05); }

/* Loader */
.loader {
  border: 3px solid rgba(255,255,255,0.1);
  border-top: 3px solid var(--primary);
  border-radius: 50%;
  width: 24px;
  height: 24px;
  animation: spin 1s linear infinite;
  display: none;
  margin: 1rem auto;
}
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }