:root {
  --bg: #f7fbff;
  --card: #ffffff;
  --muted: #5b636b;
  --accent: #8b1d3a;
  --accent-2: #0b3b78;
  --danger: #d63031;
  --glass: rgba(255, 255, 255, 0.6);
  --radius: 14px;
  --max-width: 920px;
  --gap: 1.4rem;
}

[data-theme="dark"] {
  --bg: #071426;
  --card: #0b1220;
  --muted: #9aa6b2;
  --accent: #d9b3b8;
  --accent-2: #8fb3ff;
  --danger: #ff7b7b;
}

[data-theme="dark"] body {
  background: linear-gradient(180deg, #021018 0%, #071426 100%);
  color: #e6eef8;
}

[data-theme="dark"] .calculator {
  background: linear-gradient(
    180deg,
    rgba(10, 16, 24, 0.8),
    rgba(8, 12, 18, 0.85)
  );
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6),
    inset 0 1px 0 rgba(255, 255, 255, 0.02);
}

[data-theme="dark"] .container-3d {
  background: linear-gradient(180deg, #071427, #071724);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

[data-theme="dark"] .course-inputs input,
[data-theme="dark"] .course-inputs select,
[data-theme="dark"] .previous-info input {
  background: linear-gradient(180deg, #0b1b2a, #08151f);
  color: #e6eef8;
  border: 1px solid rgba(143, 179, 255, 0.06);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.02);
}

[data-theme="dark"] .result-box {
  background: linear-gradient(180deg, #081424, #07101a);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

[data-theme="dark"] .bookmarkBtn .text {
  color: var(--muted);
}

[data-theme="dark"] .IconContainer {
  background: linear-gradient(
    180deg,
    rgba(143, 179, 255, 0.14) 0%,
    rgba(217, 179, 184, 0.14) 100%
  );
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.5);
}

[data-theme="dark"] .btn-30 {
  color: #041427;
  background: linear-gradient(90deg, var(--accent) 0%, var(--accent-2) 100%);
  box-shadow: 0 10px 30px rgba(11, 20, 40, 0.45);
}

[data-theme="dark"] .btn-30:hover {
  transform: translateY(-4px) scale(1.02);
  box-shadow: 0 24px 48px rgba(11, 20, 40, 0.55);
}

[data-theme="dark"] .result-item {
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0.02),
    rgba(255, 255, 255, 0.01)
  );
  border: 1px solid rgba(255, 255, 255, 0.02);
}

[data-theme="dark"] .course-container {
  background: linear-gradient(180deg, #06111a, #07121a);
  border: 1px solid rgba(143, 179, 255, 0.04);
}

[data-theme="dark"] .course-number {
  color: #eecfd6;
}

[data-theme="dark"] .bookmarkBtn {
  background: linear-gradient(
    90deg,
    rgba(255, 255, 255, 0.02),
    rgba(255, 255, 255, 0.01)
  );
  border: 1px solid rgba(255, 255, 255, 0.03);
  padding: 10px 16px;
}

[data-theme="dark"] .result-item .result-label {
  color: var(--muted);
}
[data-theme="dark"] .result-item .result-value {
  color: var(--accent-2);
}

[data-theme="dark"] .result-warning {
  background: linear-gradient(180deg, #2a0b0b, #200909);
  color: var(--danger);
  border-left-color: var(--danger);
}

[data-theme="dark"] .course-number {
  color: var(--accent);
}
[data-theme="dark"] .previous-info h3 {
  color: var(--muted);
}

[data-theme="dark"] .credit {
  color: var(--muted);
}
[data-theme="dark"] .credit a {
  color: var(--accent-2);
}

[data-theme="dark"] ::placeholder {
  color: rgba(255, 255, 255, 0.28);
}
[data-theme="dark"] input:focus,
[data-theme="dark"] select:focus {
  box-shadow: 0 8px 24px rgba(143, 179, 255, 0.06);
}

[data-theme="dark"] .input-error {
  box-shadow: 0 0 0 3px rgba(255, 123, 123, 0.12) !important;
  border-color: var(--danger) !important;
}

* {
  transition: color 0.18s ease, background-color 0.18s ease,
    box-shadow 0.18s ease, border-color 0.18s ease;
}
* {
  box-sizing: border-box;
}
html {
  font-size: 16px;
}
.header {
  text-align: center;
  margin-bottom: 5px;
}
body {
  margin: 0;
  min-height: 100vh;
  font-family: "Poppins", Inter, system-ui, -apple-system, "Segoe UI", Roboto,
    "Helvetica Neue", Arial;
  background: linear-gradient(180deg, var(--bg) 0%, #eef6ff 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 36px 16px;
  color: #071427;
  -webkit-font-smoothing: antialiased;
}

.calculator {
  width: 100%;
  max-width: var(--max-width);
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.9),
    rgba(250, 250, 250, 0.95)
  );
  border-radius: calc(var(--radius) + 6px);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.6);
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: var(--gap);
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
}
.logo img {
  height: 60px;
  width: auto;
  display: block;
  filter: drop-shadow(0 6px 12px rgba(11, 59, 120, 0.06));
}

h2 {
  margin: 0;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  text-align: center;
  color: var(--accent-2);
  font-weight: 600;
}

.container-3d {
  background: linear-gradient(180deg, var(--card), #fbfdff);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: 0 6px 18px rgba(12, 17, 24, 0.05);
  transition: transform 0.18s cubic-bezier(0.2, 0.9, 0.3, 1),
    box-shadow 0.18s ease;
}
.container-3d:hover {
  transform: translateY(-6px) scale(1.002);
  box-shadow: 0 20px 40px rgba(11, 20, 40, 0.08);
}

#currentSemesterCourses {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.course-container {
  display: flex;
  gap: 12px;
  align-items: center;
  padding: 12px;
  background: linear-gradient(180deg, #ffffff, #fbfcff);
  border-radius: 10px;
  border: 1px solid rgba(16, 24, 40, 0.04);
}
.course-number {
  min-width: 84px;
  color: var(--accent);
  font-weight: 700;
}
.course-inputs {
  display: flex;
  gap: 12px;
  flex: 1;
}
.course-inputs input,
.course-inputs select {
  -webkit-appearance: none;
  appearance: none;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid rgba(7, 20, 40, 0.06);
  background: linear-gradient(180deg, #ffffff, #fcfdff);
  font-size: 0.95rem;
  color: #071427;
  transition: box-shadow 0.12s ease, transform 0.12s ease;
}
.course-inputs input[type="number"] {
  max-width: 120px;
}
.course-inputs select {
  max-width: 180px;
}
.course-inputs input:focus,
.course-inputs select:focus {
  outline: none;
  box-shadow: 0 6px 18px rgba(11, 59, 120, 0.06);
  transform: translateY(-2px);
  border-color: var(--accent-2);
}

.input-error {
  box-shadow: 0 0 0 3px rgba(215, 48, 48, 0.08) !important;
  border-color: var(--danger) !important;
}

.bookmarkBtn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 14px auto 0 auto;
  padding: 10px 14px;
  border-radius: 999px;
  border: none;
  background: transparent;
  cursor: pointer;
  transition: transform 0.14s ease, box-shadow 0.14s ease;
}
.bookmarkBtn:focus {
  outline: 3px solid rgba(37, 99, 235, 0.12);
  border-radius: 999px;
}
.IconContainer {
  display: inline-grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: linear-gradient(180deg, var(--accent-2) 0%, var(--accent) 100%);
  box-shadow: 0 6px 18px rgba(16, 24, 40, 0.06);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.IconContainer .icon {
  fill: white;
  width: 18px;
  height: 18px;
}
.bookmarkBtn .text {
  font-weight: 700;
  color: #0b1220;
}
.bookmarkBtn:hover {
  transform: translateY(-4px) scale(1.02);
}

.previous-info {
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
}
.previous-info h3 {
  margin: 0;
  color: #0f172a;
}
.previous-info input {
  width: 100%;
  max-width: 320px;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid rgba(15, 23, 42, 0.06);
  font-size: 1rem;
}
.previous-info input:focus {
  outline: none;
  box-shadow: 0 8px 24px rgba(11, 59, 120, 0.06);
  border-color: var(--accent-2);
  transform: translateY(-2px);
}

.btn-30 {
  margin: 8px auto 0 auto;
  background: linear-gradient(90deg, var(--accent-2) 0%, var(--accent) 100%);
  color: white;
  padding: 12px 26px;
  border-radius: 999px;
  font-weight: 700;
  letter-spacing: 0.06em;
  cursor: pointer;
  border: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 22px rgba(11, 59, 120, 0.08);
  transition: transform 0.14s cubic-bezier(0.2, 0.9, 0.3, 1),
    box-shadow 0.14s ease;
}
.btn-30:hover {
  transform: translateY(-4px) scale(1.02);
  box-shadow: 0 20px 44px rgba(11, 59, 120, 0.12);
}
.btn-30:active {
  transform: translateY(0);
}
.btn-30:focus {
  outline: 4px solid rgba(14, 165, 164, 0.14);
}

#result {
  display: none;
}
#result.active {
  display: block;
}
.result-box {
  padding: 12px;
  border-radius: 10px;
  background: linear-gradient(180deg, #fff 0%, #f7fbfb 100%);
  border: 1px solid rgba(7, 20, 40, 0.04);
  box-shadow: 0 10px 30px rgba(11, 20, 40, 0.04);
}
.result-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  border-radius: 10px;
  background: linear-gradient(90deg, #ffffff, #fbfdff);
  margin-bottom: 10px;
  transition: transform 0.12s ease, box-shadow 0.12s ease;
}
.result-item .result-label {
  font-size: 0.82rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}
.result-item .result-value {
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--accent-2);
}

.result-warning {
  background: linear-gradient(180deg, #fff5f5, #fff9f9);
  border-left: 4px solid var(--danger);
  padding: 12px;
  border-radius: 8px;
  color: var(--danger);
}

.credit {
  text-align: center;
  color: var(--muted);
  font-size: 0.92rem;
}
.credit a {
  color: var(--accent-2);
  text-decoration: none;
  font-weight: 600;
}

@media (max-width: 720px) {
  .calculator {
    padding: 12px;
    gap: 12px;
  }
  .course-container {
    flex-direction: row;
    align-items: center;
    gap: 8px;
    padding: 10px;
  }
  .course-number {
    font-size: 0.92rem;
    min-width: 72px;
  }
  .course-inputs {
    gap: 8px;
  }
  .course-inputs input[type="number"],
  .course-inputs select {
    width: auto;
    flex: 1;
  }
  .previous-info {
    align-items: stretch;
  }
  .previous-info input {
    max-width: 100%;
  }
  .IconContainer {
    width: 38px;
    height: 38px;
  }
  .btn-30 {
    width: 100%;
  }
  .result-item .result-value {
    font-size: 1.25rem;
  }
}

@media (max-width: 420px) {
  body {
    padding: 18px;
  }
  h2 {
    font-size: 0.98rem;
  }
  .logo img {
    height: 58px;
  }
  .result-item .result-value {
    font-size: 1.35rem;
  }
}

.hidden {
  display: none;
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}