/* ============================================================
   VTU SGPA & CGPA Calculator — style.css
   Fonts: Sora (display) + Nunito (body)
   ============================================================ */

/* ── CSS Variables ───────────────────────────────────────── */
:root {
  /* Light theme */
  --bg-primary: #f0f4ff;
  --bg-secondary: #e8eeff;
  --card-bg: #ffffff;
  --card-border: rgba(79, 70, 229, 0.12);
  --card-shadow: 0 4px 24px rgba(79, 70, 229, 0.08), 0 1px 4px rgba(0,0,0,0.05);
  --card-shadow-hover: 0 8px 40px rgba(79, 70, 229, 0.15), 0 2px 8px rgba(0,0,0,0.08);

  --text-primary: #1e1b4b;
  --text-secondary: #4338ca;
  --text-muted: #6b7280;
  --text-label: #7c3aed;

  --accent-primary: #4f46e5;
  --accent-secondary: #06b6d4;
  --accent-success: #10b981;
  --accent-warning: #f59e0b;
  --accent-danger: #ef4444;

  --input-bg: #f8faff;
  --input-border: #c7d2fe;
  --input-focus: #4f46e5;
  --input-text: #1e1b4b;

  --select-bg: #f8faff;
  --select-border: #c7d2fe;

  --table-head-bg: #eef2ff;
  --table-row-alt: #f8faff;
  --table-border: #e0e7ff;

  --header-grad-1: #312e81;
  --header-grad-2: #1e40af;
  --header-grad-3: #0e7490;

  --badge-O: #fbbf24; --badge-O-text: #78350f;
  --badge-S: #34d399; --badge-S-text: #064e3b;
  --badge-A: #60a5fa; --badge-A-text: #1e3a8a;
  --badge-B: #818cf8; --badge-B-text: #312e81;
  --badge-C: #a78bfa; --badge-C-text: #4c1d95;
  --badge-D: #fb923c; --badge-D-text: #7c2d12;
  --badge-E: #94a3b8; --badge-E-text: #1e293b;
  --badge-F: #f87171; --badge-F-text: #7f1d1d;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;

  --transition: 0.22s cubic-bezier(0.4, 0, 0.2, 1);
  --font-display: 'Sora', sans-serif;
  --font-body: 'Nunito', sans-serif;
}

[data-theme="dark"] {
  --bg-primary: #0d0d1a;
  --bg-secondary: #13132a;
  --card-bg: #1a1a2e;
  --card-border: rgba(129, 140, 248, 0.15);
  --card-shadow: 0 4px 24px rgba(0,0,0,0.4), 0 1px 4px rgba(0,0,0,0.2);
  --card-shadow-hover: 0 8px 40px rgba(129, 140, 248, 0.2), 0 2px 8px rgba(0,0,0,0.3);

  --text-primary: #e2e8f0;
  --text-secondary: #a5b4fc;
  --text-muted: #94a3b8;
  --text-label: #c4b5fd;

  --accent-primary: #818cf8;
  --accent-secondary: #22d3ee;
  --accent-success: #34d399;
  --accent-warning: #fbbf24;
  --accent-danger: #f87171;

  --input-bg: #12122a;
  --input-border: #3730a3;
  --input-focus: #818cf8;
  --input-text: #e2e8f0;

  --select-bg: #12122a;
  --select-border: #3730a3;

  --table-head-bg: #1e1e40;
  --table-row-alt: #16162e;
  --table-border: #2d2d55;

  --header-grad-1: #1a0a3c;
  --header-grad-2: #0a1a40;
  --header-grad-3: #042f4a;

  --badge-O: #d97706; --badge-O-text: #fef3c7;
  --badge-S: #059669; --badge-S-text: #d1fae5;
  --badge-A: #2563eb; --badge-A-text: #dbeafe;
  --badge-B: #4f46e5; --badge-B-text: #e0e7ff;
  --badge-C: #7c3aed; --badge-C-text: #ede9fe;
  --badge-D: #ea580c; --badge-D-text: #ffedd5;
  --badge-E: #475569; --badge-E-text: #f1f5f9;
  --badge-F: #dc2626; --badge-F-text: #fee2e2;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
  line-height: 1.6;
  overflow-x: hidden;
}

/* ── Utility ─────────────────────────────────────────────── */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 18px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--card-shadow);
  padding: 32px;
  transition: box-shadow var(--transition), background var(--transition), border var(--transition);
}

.card:hover { box-shadow: var(--card-shadow-hover); }

/* ── Animations ──────────────────────────────────────────── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.92); }
  to   { opacity: 1; transform: scale(1); }
}
@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
@keyframes pulse-ring {
  0%   { transform: scale(1); opacity: 0.6; }
  100% { transform: scale(1.6); opacity: 0; }
}
@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}
@keyframes toastOut {
  from { opacity: 1; transform: translateX(0); }
  to   { opacity: 0; transform: translateX(40px); }
}

.animate-in {
  animation: fadeInUp 0.55s cubic-bezier(0.22, 1, 0.36, 1) both;
}
.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.2s; }
.animate-in:nth-child(4) { animation-delay: 0.3s; }

/* ── Header ──────────────────────────────────────────────── */
.site-header {
  position: relative;
  background: linear-gradient(135deg, var(--header-grad-1) 0%, var(--header-grad-2) 55%, var(--header-grad-3) 100%);
  padding: 28px 0 0;
  overflow: hidden;
}

.header-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 60% 80% at 20% 50%, rgba(129,140,248,0.18) 0%, transparent 70%),
    radial-gradient(ellipse 40% 60% at 80% 30%, rgba(34,211,238,0.12) 0%, transparent 70%);
  pointer-events: none;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 28px;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-icon {
  flex-shrink: 0;
  filter: drop-shadow(0 4px 12px rgba(34,211,238,0.4));
}

.brand-title {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.5px;
  line-height: 1.1;
}

.brand-sub {
  display: block;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.65);
  font-weight: 500;
  letter-spacing: 0.5px;
  margin-top: 2px;
}

.header-actions { display: flex; align-items: center; gap: 10px; }

.theme-switch {
  position: relative;
  display: inline-block;
  width: 90px;
  height: 30px;
}

.theme-switch input {
  display: none;
}

.slider {
  position: absolute;
  cursor: pointer;
  background: linear-gradient(135deg,#0f0b16,#370d91);
  border-radius: 50px;
  width: 80%;
  height: 90%;
  transition: 0.4s;
}

/* Circle */
.slider:before {
  content: "";
  position: absolute;
  height: 20px;
  width: 20px;
  left: 5px;
  bottom: 4px;
  background: rgb(230, 218, 218);
  border-radius: 50%;
  transition: 0.4s;
}

/* Sun background */
input:checked + .slider {
  background: linear-gradient(135deg,#098dd4,#f4ec15);
}

/* Move circle */
input:checked + .slider:before {
  transform: translateX(45px);
}



.theme-toggle {
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 50px;
  padding: 8px 16px;
  cursor: pointer;
  display: flex; align-items: center; gap: 6px;
  transition: background var(--transition), transform var(--transition);
  font-size: 0.95rem;
}
.theme-toggle:hover { background: rgba(255,255,255,0.22); transform: scale(1.05); }

.theme-icon { transition: opacity 0.2s; }
[data-theme="light"] .dark-icon,
[data-theme="dark"]  .light-icon { display: none; }

.header-wave {
  line-height: 0;
}
.header-wave svg { display: block; width: 100%; height: 50px; }

/* ── Main Content ─────────────────────────────────────────── */
.main-content {
  padding-top: 36px;
  padding-bottom: 64px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

/* ── Section Labels / Titles ──────────────────────────────── */
.section-label {
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-label);
  margin-bottom: 6px;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 2.5vw, 1.55rem);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 28px;
  letter-spacing: -0.3px;
}

/* ── Selector Grid ────────────────────────────────────────── */
.selector-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-bottom: 28px;
}

.selector-group { display: flex; flex-direction: column; gap: 8px; }

.selector-label {
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
}
.label-icon { font-size: 1rem; }

.select-wrapper {
  position: relative;
}

.styled-select {
  width: 100%;
  appearance: none;
  -webkit-appearance: none;
  background: var(--select-bg);
  border: 1.5px solid var(--select-border);
  border-radius: var(--radius-md);
  padding: 12px 40px 12px 16px;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  transition: border var(--transition), box-shadow var(--transition), background var(--transition);
  outline: none;
}
.styled-select:focus {
  border-color: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(79,70,229,0.15);
}
.styled-select:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}
.styled-select option {
  background: var(--card-bg);
  color: var(--text-primary);
}

.select-arrow {
  position: absolute;
  right: 14px; top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
  font-size: 1rem;
  transition: transform var(--transition);
}
.select-wrapper:focus-within .select-arrow { transform: translateY(-50%) rotate(180deg); }

.selector-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* ── Buttons ──────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: none;
  border-radius: var(--radius-md);
  padding: 12px 24px;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  letter-spacing: 0.2px;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}
.btn::after {
  content: '';
  position: absolute; inset: 0;
  background: rgba(255,255,255,0);
  transition: background 0.2s;
}
.btn:hover::after { background: rgba(255,255,255,0.08); }
.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }

.btn-icon { font-size: 1rem; transition: transform 0.2s; }
.btn:hover .btn-icon { transform: scale(1.15); }

.btn-primary {
  background: linear-gradient(135deg, var(--accent-primary), #6366f1);
  color: #fff;
  box-shadow: 0 4px 14px rgba(79,70,229,0.35);
}
.btn-primary:hover { box-shadow: 0 6px 20px rgba(79,70,229,0.5); transform: translateY(-1px); }

.btn-accent {
  background: linear-gradient(135deg, #0ea5e9, var(--accent-secondary));
  color: #fff;
  box-shadow: 0 4px 14px rgba(6,182,212,0.35);
}
.btn-accent:hover { box-shadow: 0 6px 20px rgba(6,182,212,0.5); transform: translateY(-1px); }

.btn-success {
  background: linear-gradient(135deg, #059669, #10b981);
  color: #fff;
  box-shadow: 0 4px 14px rgba(16,185,129,0.3);
}
.btn-success:hover { box-shadow: 0 6px 20px rgba(16,185,129,0.45); transform: translateY(-1px); }

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--card-border);
  color: var(--text-primary);
}
.btn-outline:hover { border-color: var(--accent-primary); color: var(--accent-primary); background: rgba(79,70,229,0.06); }

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  padding: 8px 16px;
  font-size: 0.82rem;
}
.btn-ghost:hover { background: var(--bg-secondary); color: var(--text-primary); }

.btn-sm { padding: 8px 16px; font-size: 0.8rem; }
.btn-lg { padding: 15px 32px; font-size: 1rem; }

/* ── Subjects Section ─────────────────────────────────────── */
.subjects-section { margin: 0; }
.section-header-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}
.marks-quick-fill { padding-top: 6px; }

.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

/* ── Subject Card ─────────────────────────────────────────── */
.subject-card {
  background: var(--card-bg);
  border: 1.5px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  transition: all var(--transition);
  box-shadow: var(--card-shadow);
  animation: scaleIn 0.35s cubic-bezier(0.22, 1, 0.36, 1) both;
  position: relative;
  overflow: hidden;
}
.subject-card::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 4px;
  background: linear-gradient(180deg, var(--accent-primary), var(--accent-secondary));
  border-radius: 4px 0 0 4px;
  opacity: 0;
  transition: opacity var(--transition);
}
.subject-card:hover { box-shadow: var(--card-shadow-hover); border-color: var(--accent-primary); }
.subject-card:hover::before { opacity: 1; }

.subject-card.has-grade::before { opacity: 1; }
.subject-card.grade-F-card::before { background: var(--accent-danger); }

.subject-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
}

.subject-code {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--accent-primary);
  letter-spacing: 0.8px;
  background: rgba(79,70,229,0.1);
  padding: 3px 8px;
  border-radius: 6px;
}

.subject-credits-badge {
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: 3px 8px;
  border-radius: 6px;
  white-space: nowrap;
}

.subject-name {
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 14px;
  line-height: 1.35;
  min-height: 2.4em;
}

.subject-input-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.marks-input-wrap {
  flex: 1;
  position: relative;
}

.marks-input {
  width: 100%;
  background: var(--input-bg);
  border: 1.5px solid var(--input-border);
  border-radius: var(--radius-sm);
  padding: 10px 40px 10px 14px;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--input-text);
  outline: none;
  transition: border var(--transition), box-shadow var(--transition);
}
.marks-input:focus {
  border-color: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(79,70,229,0.12);
}
.marks-input.error {
  border-color: var(--accent-danger);
  box-shadow: 0 0 0 3px rgba(239,68,68,0.12);
}
.marks-input.valid {
  border-color: var(--accent-success);
}
.marks-input-suffix {
  position: absolute;
  right: 12px; top: 50%;
  transform: translateY(-50%);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-muted);
}

.grade-display {
  width: 52px; height: 52px;
  border-radius: var(--radius-sm);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.2rem;
  background: var(--bg-secondary);
  color: var(--text-muted);
  border: 1.5px solid var(--card-border);
  transition: all var(--transition);
  flex-shrink: 0;
}
.grade-display.active {
  border: none;
}
.grade-display sub {
  font-size: 0.55rem;
  font-weight: 600;
  opacity: 0.8;
  margin-top: -2px;
}

/* Grade badge colors */
.badge-O { background: var(--badge-O); color: var(--badge-O-text); }
.badge-S { background: var(--badge-S); color: var(--badge-S-text); }
.badge-A { background: var(--badge-A); color: var(--badge-A-text); }
.badge-B { background: var(--badge-B); color: var(--badge-B-text); }
.badge-C { background: var(--badge-C); color: var(--badge-C-text); }
.badge-D { background: var(--badge-D); color: var(--badge-D-text); }
.badge-E { background: var(--badge-E); color: var(--badge-E-text); }
.badge-F { background: var(--badge-F); color: var(--badge-F-text); }

.calculate-row {
  display: flex;
  justify-content: center;
  padding: 8px 0;
}

/* ── Error Banner ─────────────────────────────────────────── */
.error-banner {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(239,68,68,0.08);
  border: 1.5px solid rgba(239,68,68,0.3);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  color: var(--accent-danger);
  font-weight: 600;
  font-size: 0.88rem;
  margin-top: 12px;
  animation: fadeInUp 0.3s ease;
}
.error-icon { font-size: 1.1rem; }

/* ── Results Section ──────────────────────────────────────── */
.results-section { margin: 0; }

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 18px;
  margin-bottom: 30px;
}

.result-card {
  border-radius: var(--radius-lg);
  padding: 24px 20px;
  text-align: center;
  animation: scaleIn 0.45s cubic-bezier(0.22, 1, 0.36, 1) both;
  position: relative;
  overflow: hidden;
}
.result-card::after {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.06), transparent);
  pointer-events: none;
}
.result-sgpa {
  background: linear-gradient(135deg, #312e81, #4f46e5);
  color: #fff;
}
.result-percent {
  background: linear-gradient(135deg, #065f46, #059669);
  color: #fff;
}
.result-grade {
  background: linear-gradient(135deg, #0c4a6e, #0ea5e9);
  color: #fff;
}

.result-label {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  opacity: 0.8;
  margin-bottom: 10px;
}
.result-value {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -1px;
  line-height: 1;
  margin-bottom: 8px;
}
.result-sub {
  font-size: 0.75rem;
  opacity: 0.7;
  font-weight: 500;
}

/* ── Breakdown Table ──────────────────────────────────────── */
.breakdown-table-wrap {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 24px;
  box-shadow: var(--card-shadow);
}
.breakdown-title {
  font-family: var(--font-display);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-muted);
  padding: 16px 22px 12px;
  border-bottom: 1px solid var(--table-border);
  letter-spacing: 0.3px;
}
.table-responsive { overflow-x: auto; }

.breakdown-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}
.breakdown-table th {
  background: var(--table-head-bg);
  padding: 11px 14px;
  text-align: left;
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.8px;
  text-transform: uppercase;
  border-bottom: 1px solid var(--table-border);
  white-space: nowrap;
}
.breakdown-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--table-border);
  color: var(--text-primary);
  font-weight: 500;
}
.breakdown-table tr:last-child td { border-bottom: none; }
.breakdown-table tr:nth-child(even) td { background: var(--table-row-alt); }
.breakdown-table tfoot td {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 0.88rem;
  background: var(--table-head-bg);
  border-top: 2px solid var(--card-border);
  color: var(--text-primary);
}

.grade-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px; height: 32px;
  border-radius: 8px;
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 800;
}
.fail-row td { color: var(--accent-danger) !important; }

.save-row {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.save-hint {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-style: italic;
}

/* ── CGPA Section ─────────────────────────────────────────── */
.cgpa-section { }
.cgpa-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 6px;
}
.cgpa-header .section-title { margin-bottom: 24px; }

.cgpa-semesters { margin-bottom: 24px; }

.cgpa-empty {
  text-align: center;
  padding: 36px 20px;
  color: var(--text-muted);
}
.cgpa-empty-icon { font-size: 2.5rem; display: block; margin-bottom: 12px; }
.cgpa-empty p { font-size: 0.88rem; line-height: 1.6; }

.cgpa-rows {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 14px;
  margin-bottom: 24px;
}

.cgpa-sem-card {
  background: var(--bg-secondary);
  border: 1.5px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
  position: relative;
  animation: scaleIn 0.35s ease both;
  transition: all var(--transition);
}
.cgpa-sem-card:hover { border-color: var(--accent-primary); }

.cgpa-sem-label {
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 6px;
}
.cgpa-sem-value {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent-primary);
  margin-bottom: 4px;
}
.cgpa-sem-credits {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 500;
}
.cgpa-sem-remove {
  position: absolute;
  top: 8px; right: 8px;
  background: none; border: none;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1;
  padding: 2px;
  border-radius: 4px;
  transition: color var(--transition), background var(--transition);
}
.cgpa-sem-remove:hover { color: var(--accent-danger); background: rgba(239,68,68,0.1); }

.cgpa-result-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 28px;
}
.cgpa-result-card {
  background: linear-gradient(135deg, rgba(79,70,229,0.12), rgba(6,182,212,0.08));
  border: 1.5px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 20px;
  text-align: center;
}
.cgpa-eq-label {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.cgpa-eq-value {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent-primary);
}

/* Manual CGPA entry */
.manual-entry-section {
  border-top: 1px solid var(--card-border);
  padding-top: 24px;
  margin-top: 8px;
}
.manual-title {
  font-family: var(--font-display);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 16px;
}
.manual-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
  margin-bottom: 20px;
}
.manual-input-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.manual-input-label {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}
.manual-input {
  background: var(--input-bg);
  border: 1.5px solid var(--input-border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--input-text);
  outline: none;
  transition: border var(--transition), box-shadow var(--transition);
}
.manual-input:focus {
  border-color: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(79,70,229,0.12);
}

/* ── Grade Reference ──────────────────────────────────────── */
.grade-ref-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}
.grade-ref-card {
  border-radius: var(--radius-md);
  padding: 16px 10px;
  text-align: center;
  animation: scaleIn 0.4s cubic-bezier(0.22, 1, 0.36, 1) both;
  transition: transform var(--transition), box-shadow var(--transition);
}
.grade-ref-card:hover { transform: translateY(-4px) scale(1.04); box-shadow: 0 8px 24px rgba(0,0,0,0.12); }

.grade-letter {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 6px;
}
.grade-range { font-size: 0.72rem; font-weight: 700; opacity: 0.8; margin-bottom: 3px; }
.grade-points { font-size: 0.75rem; font-weight: 800; margin-bottom: 4px; }
.grade-tag { font-size: 0.62rem; font-weight: 600; letter-spacing: 0.5px; opacity: 0.7; }

/* Grade ref card colors */
.grade-O { background: #fef3c7; color: #92400e; }
.grade-S { background: #d1fae5; color: #065f46; }
.grade-A { background: #dbeafe; color: #1e3a8a; }
.grade-B { background: #ede9fe; color: #4c1d95; }
.grade-C { background: #fce7f3; color: #831843; }
.grade-D { background: #ffedd5; color: #7c2d12; }
.grade-E { background: #f1f5f9; color: #334155; }
.grade-F { background: #fee2e2; color: #7f1d1d; }

[data-theme="dark"] .grade-O { background: #44340a; color: #fef3c7; }
[data-theme="dark"] .grade-S { background: #052e16; color: #d1fae5; }
[data-theme="dark"] .grade-A { background: #0c1f4a; color: #bfdbfe; }
[data-theme="dark"] .grade-B { background: #2a1a4e; color: #ede9fe; }
[data-theme="dark"] .grade-C { background: #3d0a23; color: #fce7f3; }
[data-theme="dark"] .grade-D { background: #3c1006; color: #ffedd5; }
[data-theme="dark"] .grade-E { background: #1a2030; color: #e2e8f0; }
[data-theme="dark"] .grade-F { background: #450a0a; color: #fee2e2; }

/* ── Formula Box ──────────────────────────────────────────── */
.formula-box {
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.formula-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  flex-wrap: wrap;
  font-size: 0.85rem;
}
.formula-label {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--text-muted);
  white-space: nowrap;
  min-width: 120px;
  font-size: 0.8rem;
}
.formula-text {
  font-family: 'Courier New', monospace;
  font-weight: 700;
  color: var(--accent-primary);
  background: rgba(79,70,229,0.08);
  padding: 2px 8px;
  border-radius: 6px;
  font-size: 0.82rem;
  word-break: break-all;
}

/* ── Footer ───────────────────────────────────────────────── */
.site-footer {
  background: var(--card-bg);
  border-top: 1px solid var(--card-border);
  padding: 24px 0;
  text-align: center;
}
.footer-content { display: flex; flex-direction: column; gap: 6px; align-items: center; }
.site-footer p { font-size: 0.82rem; color: var(--text-muted); }
.footer-note { font-size: 0.75rem; opacity: 0.7; }

/* ── Toast ────────────────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 28px; right: 28px;
  background: #1e1b4b;
  color: #fff;
  padding: 14px 22px;
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-size: 0.88rem;
  font-weight: 600;
  box-shadow: 0 8px 32px rgba(0,0,0,0.3);
  z-index: 9999;
  display: none;
  max-width: 320px;
}
.toast.show { display: block; animation: toastIn 0.35s ease; }
.toast.hide { animation: toastOut 0.35s ease forwards; }
[data-theme="dark"] .toast { background: #4f46e5; }

/* ── Loading Shimmer ──────────────────────────────────────── */
.shimmer {
  background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--card-border) 50%, var(--bg-secondary) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
  border-radius: var(--radius-sm);
  height: 14px;
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 768px) {
  .selector-grid { grid-template-columns: 1fr; }
  .results-grid { grid-template-columns: 1fr; }
  .cgpa-result-row { grid-template-columns: 1fr; }
  .subjects-grid { grid-template-columns: 1fr; }
  .grade-ref-grid { grid-template-columns: repeat(4, 1fr); }
  .card { padding: 22px 18px; }
  .brand-title { font-size: 1.2rem; }
  .manual-grid { grid-template-columns: repeat(2, 1fr); }
  .cgpa-rows { grid-template-columns: repeat(2, 1fr); }
  .breakdown-table { font-size: 0.78rem; }
  .breakdown-table th, .breakdown-table td { padding: 9px 10px; }
}

@media (max-width: 480px) {
  .container { padding: 0 14px; }
  .grade-ref-grid { grid-template-columns: repeat(4, 1fr); gap: 8px; }
  .grade-letter { font-size: 1.5rem; }
  .grade-range { font-size: 0.62rem; }
  .grade-tag { display: none; }
  .selector-actions { flex-direction: column; }
  .selector-actions .btn { width: 100%; justify-content: center; }
  .cgpa-result-row { grid-template-columns: 1fr; }
  .results-grid { grid-template-columns: 1fr; }
  .save-row { flex-direction: column; align-items: flex-start; }
  .formula-item { flex-direction: column; gap: 4px; }
}

@media (min-width: 900px) {
  .grade-ref-grid { grid-template-columns: repeat(8, 1fr); }
}

/* ── Scrollbar ────────────────────────────────────────────── */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--card-border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent-primary); }

/* ── Selection ────────────────────────────────────────────── */
::selection { background: rgba(79,70,229,0.2); color: var(--text-primary); }