* {
  box-sizing: border-box;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  margin: 0;
  background: #ffffff;
  color: #0f172a;
}

/* HERO */
/* HERO WRAPPER */
.hero {
  position: relative;
  padding: 60px 20px 40px;
  max-width: 1100px;
  margin: auto;
}

/* TOP LEFT BRAND */
.top-brand {
  position: absolute;
  top: 20px;
  left: 20px;
  text-align: left;
}

.brand-name {
  font-size: 14px;
  font-weight: 700;
  color: #0f172a;
}

.brand-tagline {
  font-size: 13px;
  color: #475569;
  margin-top: 2px;
}

/* TEAL HIGHLIGHT PILL */
.ai-pill {
  display: inline-block;
  margin-top: 6px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  color: #0d9488;
  background: #ccfbf1; /* light teal */
  border-radius: 999px;
}

/* CENTER CONTENT */
.hero-content {
  text-align: center;
  margin-top: 80px;
}

.hero-title {
  font-size: 44px;
  line-height: 1.2;
  font-weight: 700;
  color: #0f172a;
}

/* TEAL MAIN HIGHLIGHT */
.hero-highlight {
  color: #0d9488;
  font-weight: 800;
}

/* SUBTEXT */
.hero-description {
  margin-top: 16px;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
  font-size: 17px;
  font-weight: 400;
  color: #64748b; /* thin grey */
}


/* MAIN */
.container {
  max-width: 900px;
  margin: auto;
  padding: 30px 20px;
}

.card {
  background: #f8fafc;
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 20px;
  border: 1px solid #e2e8f0;
}

h3 {
  margin-bottom: 10px;
}

label {
  display: block;
  margin-top: 10px;
  font-weight: 500;
}

input, select {
  width: 100%;
  padding: 10px;
  margin-top: 6px;
  border-radius: 10px;
  border: 1px solid #cbd5f5;
  font-size: 14px;
}

button {
  margin-top: 14px;
  padding: 10px 16px;
  border: none;
  border-radius: 12px;
  background: linear-gradient(135deg, #6366f1, #9333ea);
  color: white;
  font-weight: 600;
  cursor: pointer;
}

button:hover {
  opacity: 0.9;
}

.generate-btn {
  width: 100%;
  font-size: 18px;
  margin-top: 10px;
}

.hint {
  font-size: 13px;
  color: #dc2626;
  margin-top: 10px;
}

/* LIST */
ul {
  padding-left: 16px;
  margin-top: 10px;
}

/* LOADING */
.loading {
  text-align: center;
  margin-top: 30px;
}

.loader {
  width: 50px;
  height: 50px;
  border: 5px solid #e5e7eb;
  border-top-color: #6366f1;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: auto;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.hidden {
  display: none;
}

/* TIMETABLE */
.day {
  background: #f1f5f9;
  border-radius: 14px;
  padding: 16px;
  margin-top: 16px;
}

.block {
  background: #ffffff;
  border-radius: 10px;
  padding: 8px;
  margin-top: 8px;
  font-size: 14px;
  border: 1px solid #e2e8f0;
}

/* FOOTER */
footer {
  text-align: center;
  padding: 30px;
  font-size: 14px;
  color: #64748b;
}

/* SUMMARY */
.timetable-summary h3 {
  margin-bottom: 6px;
}

.date-range {
  color: #64748b;
  margin-bottom: 14px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  text-align: center;
}

.stats strong {
  font-size: 22px;
  color: #0d9488;
}

.stats span {
  display: block;
  font-size: 12px;
  color: #64748b;
}

/* TIPS */
.tips {
  padding-left: 18px;
  color: #475569;
}

/* DAY SCHEDULE */
.day-block {
  margin-top: 20px;
}

.day-header {
  font-weight: 700;
  margin-bottom: 8px;
}

.session {
  display: grid;
  grid-template-columns: 1fr 80px 60px;
  padding: 8px 12px;
  margin-top: 6px;
  border-radius: 10px;
  background: #ffffff;
  border: 1px solid #e2e8f0;
  font-size: 14px;
}

.session.break {
  background: #f1f5f9;
  color: #64748b;
}