:root {
  --bg-color: #ffffff;
  --card-bg: #f3f4f6;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --accent-color: #3f8cff;

  /* Toast colors */
  --toast-success: #22c55e; /* green-500 */
  --toast-error: #ef4444; /* red-500 */
  --toast-info: #3b82f6;

  --subject-rwd: #6c5dd3;
  --subject-cms: #00b894;
  --subject-imk: #eb4d8d;
  --subject-adp: #ffb84c;
  --subject-uxe: #a3e635;
  --subject-dfs: #38bdf8;
  --subject-cah: #f9f925;
  --subject-lfs: #dedede;
  --subject-sw: #dedede;
}

[data-theme='dark'] {
  --bg-color: #1e1e2f;
  --card-bg: #2a2b3c;
  --text-primary: #f4f4f5;
  --text-secondary: #a0a3b1;
  --accent-color: #3f8cff;

  /* Toast colors */
  --toast-success: #4ade80; /* lighter green */
  --toast-error: #f87171; /* soft red */
  --toast-info: #60a5fa;

  --subject-rwd: #6c5dd3;
  --subject-cms: #00b894;
  --subject-imk: #eb4d8d;
  --subject-adp: #ffb84c;
  --subject-uxe: #a3e635;
  --subject-cah: #f9f925;
  --subject-lfs: #eaeaea;
  --subject-sw: #eaeaea;
  --subject-dfs: #38bdf8;
}

/* Reset & base layout */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-family: 'Segoe UI', sans-serif;
  line-height: 1.6;
  transition: background-color 0.3s, color 0.3s;
}

/* Typography */
h1 {
  font-size: 1.2rem;
}

h2 {
  font-size: 1.44rem;
  margin-bottom: 0.5rem;
}

h3 {
  font-size: 1.2rem;
  margin-bottom: 0.25rem;
}

h4 {
  font-size: 1rem;
  text-align: center;
  color: var(--accent-color);
  margin-bottom: 0.5rem;
}

p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 1rem 2rem;
}

/* Header/Footer */
header {
  position: sticky;
  top: 0;
  background-color: var(--bg-color);
  --shadow: hsla(0 0% 0% / 0.1) 0 0.5rem 1rem;
  /* Fall back to persistent shadow */
  box-shadow: var(--shadow);
}

@supports (animation-timeline: scroll()) {
  header {
    animation: scroll-shadow linear both;
    animation-timeline: scroll();
    animation-range: 0ex 5ex;
  }

  @keyframes scroll-shadow {
    from {
      box-shadow: none;
    }

    to {
      box-shadow: var(--shadow);
    }
  }
}

.logo-theme {
  margin: 2rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Brand */
.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand img {
  width: 20px;
  height: auto;
}

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

/* Theme Toggle */
.icon-toggle,
.icon-clear {
  background: none;
  border: 1px solid var(--card-bg);
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 6px;
  transition: background-color 0.3s;
}
.icon-toggle:hover,
.icon-clear:hover {
  background-color: var(--card-bg);
}

/* Controls container */
.controls {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
}

/* Tabs */
.day-tabs,
.class-tabs {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.day-tab,
.class-tab {
  background-color: transparent;
  border: 2px solid var(--card-bg);
  color: var(--text-primary);
  padding: 0.4rem 0.8rem;
  border-radius: 0.375rem;
  cursor: pointer;
  font-weight: 500;
  flex-shrink: 0;
  transition: background-color 0.2s, color 0.2s;
}

.day-tab.active,
.class-tab.active,
.day-tab:hover,
.class-tab:hover {
  background-color: var(--accent-color);
  color: #fff;
  border-color: var(--accent-color);
}

/* My Subjects Toggle */
.switch {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  position: relative;
  cursor: pointer;
}
.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.slider {
  width: 40px;
  height: 20px;
  background-color: #ccc;
  border-radius: 20px;
  position: relative;
  transition: background-color 0.3s ease;
}
.slider::before {
  content: '';
  position: absolute;
  width: 16px;
  height: 16px;
  left: 2px;
  top: 2px;
  background-color: white;
  border-radius: 50%;
  transition: transform 0.3s ease;
}
input:checked + .slider {
  background-color: var(--accent-color);
}
input:checked + .slider::before {
  transform: translateX(20px);
}
.switch-label {
  font-weight: 500;
  color: var(--text-primary);
}

/* Schedule Layout */
.schedule-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.class-column {
  background-color: var(--card-bg);
  border-radius: 0.5rem;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.empty-state {
  max-width: 300px;
  margin: 2rem auto;
  text-align: center;
  color: var(--text-secondary);
}

.empty-state p {
  margin-top: 1rem;
}

/* Cards */
.card {
  background-color: var(--card-bg);
  padding: 1rem;
  border-radius: 0.75rem;
  display: flex;
  align-items: stretch;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
}

.card-info {
  display: flex;
  justify-content: space-between;
  flex-grow: 1;
}

.card-info > div {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.subject-bar {
  width: 12px;
  min-height: 50px;
  border-radius: 4px;
  margin-right: 1rem;
  flex-shrink: 0;
}

.subject-rwd {
  background-color: var(--subject-rwd);
}
.subject-cms {
  background-color: var(--subject-cms);
}
.subject-imk {
  background-color: var(--subject-imk);
}
.subject-adp {
  background-color: var(--subject-adp);
}
.subject-uxe {
  background-color: var(--subject-uxe);
}
.subject-dfs {
  background-color: var(--subject-dfs);
}
.subject-cah {
  background-color: var(--subject-cah);
}
.subject-lfs {
  background-color: var(--subject-lfs);
}
.subject-sw {
  background-color: var(--subject-sw);
}

@media screen and (max-width: 768px) {
  .controls {
    flex-direction: column;
    gap: 1rem;
  }
}

.theme-toggle-btn {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  display: inline-flex;
  align-items: center;
}

.theme-icon {
  width: 24px;
  height: 24px;
  transition: transform 0.4s ease;
}

.theme-icon-sun,
.theme-icon-moon {
  transform-origin: center;
  transition: opacity 0.4s ease, transform 0.4s ease;
}

.theme-icon-sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}
.theme-icon-moon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.8);
}

[data-theme='dark'] .theme-icon-sun {
  opacity: 0;
  transform: rotate(90deg) scale(0.8);
}
[data-theme='dark'] .theme-icon-moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.toast {
  position: fixed;
  top: 3rem;
  left: 50%;
  width: max-content;
  transform: translateX(-50%);
  background-color: var(--bg-color);
  border: 2px solid var(--toast-info);
  color: var(--toast-info);
  padding: 0.75rem 1.25rem;
  border-radius: 0.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
  z-index: 999;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
  pointer-events: auto;
}