@import url('https://fonts.googleapis.com/css2?family=Syne:wght@400;600;700;800&family=DM+Sans:wght@300;400;500&display=swap');

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

:root {
  --bg:        #0e0f14;
  --surface:   #16181f;
  --surface2:  #1e2029;
  --border:    #2a2d3a;
  --accent:    #f5c842;
  --accent2:   #e8743a;
  --text:      #e8eaf0;
  --text-muted:#7a7f9a;
  --radius:    12px;
  --shadow:    0 4px 24px rgba(0,0,0,0.4);
}

/* ── Base ────────────────────────────────────────────── */
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-weight: 400;
  min-height: 100vh;
  padding: clamp(1.5rem, 5vw, 4rem) clamp(1rem, 5vw, 3rem);
  max-width: 900px;
  margin: 0 auto;
  
  /* subtle grid texture */
  background-image:
    linear-gradient(rgba(245,200,66,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245,200,66,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
}

/* ── Header ──────────────────────────────────────────── */
h1#courseName {
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  font-size: clamp(2rem, 6vw, 3.5rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.3rem;
}

h2#courseCode {
  font-family: 'Syne', sans-serif;
  font-weight: 600;
  font-size: clamp(0.9rem, 2.5vw, 1.1rem);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: clamp(2rem, 5vw, 3rem);
}

/* ── Enroll Controls ─────────────────────────────────── */
.enroll-row {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
  align-items: center;
}

label[for="sectionNumber"] {
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  width: 100%;
}

/* wrap label + input + button together */
body > label,
body > input,
body > button {
  display: block;
}

body > label {
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
}

input#sectionNumber {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-size: 1rem;
  padding: 0.7rem 1rem;
  width: min(100%, 200px);
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
  margin-bottom: 0.75rem;
}

input#sectionNumber:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(245,200,66,0.15);
}

input#sectionNumber::placeholder {
  color: var(--text-muted);
}

button#enrollStudent {
  background: var(--accent);
  color: #0e0f14;
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: none;
  border-radius: var(--radius);
  padding: 0.75rem 1.5rem;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s, background 0.2s;
  box-shadow: 0 2px 12px rgba(245,200,66,0.3);
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

button#enrollStudent:hover {
  background: #ffd95a;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(245,200,66,0.45);
}

button#enrollStudent:active {
  transform: translateY(0);
}

/* ── Table ───────────────────────────────────────────── */
table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: var(--surface);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

thead tr {
  background: var(--surface2);
}

th {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding: 1rem 1.25rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

td {
  padding: 0.9rem 1.25rem;
  font-size: clamp(0.85rem, 2vw, 0.95rem);
  color: var(--text);
  border-bottom: 1px solid var(--border);
  transition: background 0.15s;
}

tbody tr:last-child td {
  border-bottom: none;
}

tbody tr:hover td {
  background: rgba(245,200,66,0.04);
}

/* highlight the enrolled count column */
td:nth-child(3) {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  color: var(--accent);
}

/* ── Responsive: tablet ──────────────────────────────── */
@media (max-width: 640px) {
  /* stack table as cards on mobile */
  table, thead, tbody, th, td, tr {
    display: block;
  }

  thead tr {
    display: none; /* hide header row */
  }

  tbody tr {
    background: var(--surface2);
    border-radius: var(--radius);
    margin-bottom: 0.75rem;
    border: 1px solid var(--border);
    padding: 0.75rem;
    overflow: hidden;
  }

  td {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0.75rem;
    border-bottom: 1px solid rgba(255,255,255,0.05);
    font-size: 0.9rem;
  }

  td:last-child {
    border-bottom: none;
  }

  /* add labels via data-label on each td */
  td::before {
    content: attr(data-label);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
    font-family: 'Syne', sans-serif;
    font-weight: 600;
  }
}