:root {
    --primary-hue: 250;
    --primary: hsl(var(--primary-hue), 80%, 60%);
    --primary-dark: hsl(var(--primary-hue), 80%, 40%);
    --accent: hsl(320, 80%, 60%);
    --bg-gradient: linear-gradient(135deg, hsl(240, 30%, 10%), hsl(280, 40%, 15%));
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --text-main: #ffffff;
    --text-muted: rgba(255, 255, 255, 0.7);
    --card-bg: rgba(255, 255, 255, 0.07);
    --card-hover: rgba(255, 255, 255, 0.12);

    --font-ar: 'Cairo', sans-serif;
    --font-en: 'Inter', sans-serif;
}

[data-theme="light"] {
    --bg-gradient: linear-gradient(135deg, #f5f7fa, #c3cfe2);
    --glass-bg: rgba(255, 255, 255, 0.6);
    --glass-border: rgba(255, 255, 255, 0.4);
    --text-main: #333333;
    --text-muted: #666666;
    --card-bg: rgba(255, 255, 255, 0.8);
    --card-hover: rgba(255, 255, 255, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-ar);
    background: var(--bg-gradient);
    color: var(--text-main);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
    scroll-behavior: smooth;
}

body[lang="en"] {
    font-family: var(--font-en);
}

.app-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header & Controls */
.controls-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
    margin-bottom: 20px;
}

.logo-area {
    font-size: 1.2rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--primary);
}

.actions {
    display: flex;
    gap: 15px;
    align-items: center;
}

.btn-glass {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-main);
    padding: 8px 16px;
    border-radius: 12px;
    cursor: pointer;
    font-family: inherit;
    font-weight: 600;
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-glass:hover {
    background: var(--card-hover);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.btn-glass.primary {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.btn-glass.primary:hover {
    background: var(--primary-dark);
}

.export-group {
    display: flex;
    gap: 8px;
}

/* Main Timetable Area */
.timetable-wrapper {
    width: 100%;
    margin-bottom: 40px;
}

.glass-panel {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 30px;
    backdrop-filter: blur(15px);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

.timetable-header {
    text-align: center;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 20px;
}

.timetable-header h1 {
    font-size: 2rem;
    margin-bottom: 5px;
    color: var(--text-main);
}

.timetable-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.meta-info {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 10px;
    font-weight: 600;
    color: var(--accent);
}

/* Schedule Grid */
.schedule-container {
    display: grid;
    gap: 20px;
}

/* Day Row Styles */
.day-row {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 15px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    border-left: 5px solid var(--primary);
    transition: transform 0.2s;
}

.day-row:hover {
    transform: translateX(5px);
    background: var(--card-hover);
}

/* Make RTL transform work correctly */
html[dir="rtl"] .day-row:hover {
    transform: translateX(-5px);
}

.day-header {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 120px;
}

.sessions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
    flex-grow: 1;
}

.session-card {
    background: rgba(0, 0, 0, 0.2);
    padding: 15px;
    border-radius: 10px;
    border: 1px solid var(--glass-border);
}

.session-card.lab {
    border-right: 3px solid #4caf50;
}

html[dir="ltr"] .session-card.lab {
    border-right: none;
    border-left: 3px solid #4caf50;
}

.session-card.theory {
    border-right: 3px solid #2196f3;
}

html[dir="ltr"] .session-card.theory {
    border-right: none;
    border-left: 3px solid #2196f3;
}

.session-title {
    font-weight: 700;
    margin-bottom: 5px;
    font-size: 1.1rem;
}

.session-info {
    font-size: 0.9rem;
    color: var(--text-muted);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.info-row {
    display: flex;
    align-items: center;
    gap: 8px;
}

.tag {
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
}

.tag.lab {
    background: rgba(76, 175, 80, 0.2);
    color: #81c784;
}

.tag.theory {
    background: rgba(33, 150, 243, 0.2);
    color: #64b5f6;
}

/* Desktop View enhancement: Row layout for days */
@media (min-width: 768px) {
    .day-row {
        flex-direction: row;
        align-items: flex-start;
    }

    .day-header {
        width: 150px;
        flex-shrink: 0;
        padding-top: 15px;
        font-size: 1.4rem;
    }
}

.timetable-footer {
    margin-top: 30px;
    padding-top: 15px;
    border-top: 1px solid var(--glass-border);
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    color: var(--text-muted);
    flex-direction: column;
    align-items: center;
    gap: 10px;
    text-align: center;
}

.designed-by {
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    color: var(--accent);
    opacity: 0.8;
    letter-spacing: 1px;
    text-transform: uppercase;
    font-weight: 700;
    margin-top: 5px;
}

/* Mobile Enhancements */
@media (max-width: 480px) {
    .app-container {
        padding: 10px;
    }

    .glass-panel {
        padding: 15px;
    }

    .timetable-header h1 {
        font-size: 1.5rem;
    }

    .session-card {
        padding: 12px;
    }

    .session-title {
        font-size: 1rem;
    }

    .controls-header {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .logo-area {
        justify-content: center;
        width: 100%;
        flex-direction: column;
        /* Stack icon and text for better look */
        gap: 8px;
    }

    #dept-name {
        font-size: 1.1rem;
        line-height: 1.4;
        /* Apply the pro gradient here too */
        background: linear-gradient(to right, var(--primary), var(--accent));
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
        display: inline-block;
    }

    .actions {
        width: 100%;
        justify-content: center;
    }

    .btn-glass {
        padding: 6px 12px;
        font-size: 0.9rem;
    }
}

/* Loading/Export Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    color: white;
    font-size: 1.5rem;
    backdrop-filter: blur(5px);
}