:root {
    --primary: #0a1045;
    --primary-light: #1b266b;
    --secondary: #00796b;
    --danger: #e91e63;
    --success: #4caf50;
    --background: #f4f7f9;
    --card-bg: #ffffff;
    --text-main: #333333;
    --text-muted: #666666;
    --border-color: #e0e0e0;
    --shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    --radius: 16px;
    --transition: all 0.2s ease;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Outfit', sans-serif;
}

body {
    background: linear-gradient(135deg, #f4f7f9 0%, #e9eff5 100%);
    color: var(--text-main);
    line-height: 1.6;
    padding: 40px 20px;
    min-height: 100vh;
}

.app-container {
    max-width: 900px;
    margin: 0 auto;
}

header {
    margin-bottom: 30px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: 1px;
}

.settings-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition);
}

.settings-btn:hover {
    color: var(--primary);
    transform: rotate(45deg);
}

.calculator-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 30px;
    margin-bottom: 30px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.8);
}

.card-header h2 {
    font-size: 18px;
    color: var(--primary);
    margin-bottom: 20px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.disclaimer {
    font-size: 11px;
    color: #999;
    font-weight: 400;
    letter-spacing: 0;
}

.table-container {
    width: 100%;
    margin-bottom: 20px;
}

.table-header {
    display: grid;
    grid-template-columns: 1fr 2fr 0.8fr 3fr 1fr 0.5fr;
    gap: 15px;
    padding: 10px 15px;
    font-weight: 600;
    color: var(--secondary);
    font-size: 13px;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 10px;
}

.subject-row {
    display: grid;
    grid-template-columns: 1fr 2fr 0.8fr 3fr 1fr 0.5fr;
    gap: 15px;
    padding: 15px;
    align-items: center;
    background: #fcfcfc;
    border-radius: 8px;
    margin-bottom: 10px;
    transition: var(--transition);
    border: 1px solid transparent;
    animation: slideIn 0.3s ease-out;
}

.subject-row:hover {
    background: #ffffff;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    border-color: var(--border-color);
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

input, select {
    width: 100%;
    padding: 10px 8px; /* Slightly reduced padding for grid fit */
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 13px; /* Slightly smaller font for compact feel */
    color: var(--text-main);
    background: #f9f9f9;
    transition: var(--transition);
}

input.error, select.error {
    border-color: var(--danger) !important;
    background-color: #fff5f5 !important;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--secondary);
    background: #ffffff;
    box-shadow: 0 0 0 3px rgba(0, 121, 107, 0.1);
}

.assessment-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 8px;
}

.grade-input-group {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.input-s1-marks, .input-s2-marks {
    padding: 6px 8px;
    font-size: 11px;
    background: #fff3e0;
    border-color: #ffb74d;
}

.lab-input {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.lab-toggle-btn {
    font-size: 10px;
    padding: 2px 5px;
    margin-top: 4px;
    background: #eee;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.lab-toggle-btn.active {
    background: var(--danger);
    color: white;
}

.result-grade {
    font-weight: 700;
    text-align: center;
    color: var(--primary);
    font-size: 16px;
}

.delete-btn {
    background: none;
    border: none;
    color: #ccc;
    cursor: pointer;
    font-size: 18px;
    transition: var(--transition);
    display: flex;
    justify-content: center;
}

.delete-btn:hover {
    color: var(--danger);
    transform: scale(1.2);
}

.card-actions {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 20px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-light); transform: translateY(-2px); }

.btn-secondary { background: var(--secondary); color: white; }
.btn-secondary:hover { background: #00695c; transform: translateY(-2px); }

.btn-danger { background: var(--danger); color: white; }
.btn-danger:hover { background: #d81b60; transform: translateY(-2px); }

.btn:active { transform: scale(0.95); }

.btn-large {
    width: 100%;
    max-width: 200px;
    padding: 15px 30px;
    font-size: 16px;
    margin: 0 auto;
}

.calculate-container {
    display: flex;
    justify-content: center;
}

.results-section {
    margin-top: 40px;
    animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.results-card {
    background: var(--primary);
    color: white;
    border-radius: var(--radius);
    padding: 30px;
    text-align: center;
}

.results-card h3 {
    font-size: 16px;
    opacity: 0.8;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.sgpa-display {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 20px;
}

.sgpa-display .value {
    font-size: 64px;
    font-weight: 700;
}

.results-details {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 15px;
    margin-top: 20px;
    text-align: left;
}

.detail-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 15px;
    border-radius: 8px;
    backdrop-filter: blur(5px);
}

.detail-item .course-name {
    font-weight: 600;
    font-size: 14px;
    display: block;
    margin-bottom: 5px;
}

.detail-item .course-stats {
    font-size: 12px;
    opacity: 0.7;
}

/* Utilities */
.hidden { display: none !important; }

@media (max-width: 768px) {
    .table-header { display: none; }
    .subject-row {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    .assessment-inputs {
        grid-template-columns: 1fr 1fr;
    }
}