:root {
    --bg-color: #030712;
    --card-bg: rgba(30, 41, 59, 0.7);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-primary: #3b82f6;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    background-image:
        radial-gradient(at 0% 0%, rgba(59, 130, 246, 0.15) 0px, transparent 50%),
        radial-gradient(at 100% 0%, rgba(139, 92, 246, 0.15) 0px, transparent 50%);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Header */
.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    padding: 1rem 1.5rem;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    border-radius: 1rem;
    position: sticky;
    top: 1rem;
    z-index: 50;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

h1 {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    color: var(--text-primary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 0.6rem 1.2rem;
    border-radius: 0.75rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    cursor: pointer;
    font-size: 0.875rem;
    gap: 0.5rem;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.4);
}

.btn-outline {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border-color: rgba(255, 255, 255, 0.2);
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    padding: 1.5rem;
    border-radius: 1rem;
    border: 1px solid var(--card-border);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
    border-color: rgba(59, 130, 246, 0.3);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1.2;
    letter-spacing: -0.02em;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    margin-top: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.progress-container {
    width: 100%;
    height: 6px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 999px;
    margin-top: 1rem;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 999px;
    transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
}

/* User Header */
.user-header {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: linear-gradient(to right, rgba(30, 41, 59, 0.5), transparent);
    border-radius: 1rem;
    border: 1px solid var(--card-border);
}

.user-avatar {
    width: 48px;
    height: 48px;
    background: var(--accent-gradient);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
    font-size: 1.25rem;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.user-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Marks Grid */
.marks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.mark-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border-radius: 1rem;
    padding: 1.5rem;
    border: 1px solid var(--card-border);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.mark-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px -8px rgba(0, 0, 0, 0.3);
    border-color: rgba(59, 130, 246, 0.3);
}



.mark-card.status-danger {
    border: 1px solid var(--danger);
}

.mark-card.status-danger:hover {
    border-color: var(--danger);
    box-shadow: 0 12px 24px -8px rgba(239, 68, 68, 0.2);
}

.mark-card.status-warning {
    border: 1px solid var(--warning);
}

.mark-card.status-warning:hover {
    border-color: var(--warning);
    box-shadow: 0 12px 24px -8px rgba(245, 158, 11, 0.2);
}

.mark-card.status-success {
    border: 1px solid var(--success);
}

.mark-card.status-success:hover {
    border-color: var(--success);
    box-shadow: 0 12px 24px -8px rgba(16, 185, 129, 0.2);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.course-code {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.session-badge {
    font-size: 0.75rem;
    padding: 0.35rem 0.75rem;
    background: rgba(59, 130, 246, 0.15);
    color: var(--text-primary);
    border-radius: 9999px;
    font-weight: 600;
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.course-desc {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 2rem;
    line-height: 1.5;
    height: 2.8em;
    overflow: hidden;
    display: -webkit-box;
    line-clamp: 2;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--card-border);
}

.mark-value {
    font-size: 2.25rem;
    font-weight: 800;
    line-height: 1;
    color: var(--text-primary);
}

.mark-label {
    font-size: 0.7rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
    font-weight: 600;
}

.status-text {
    font-size: 0.875rem;
    font-weight: 600;
    padding: 0.25rem 0.75rem;
    border-radius: 0.5rem;
    background: rgba(255, 255, 255, 0.05);
}

.status-pass {
    color: var(--text-primary);
    background: rgba(16, 185, 129, 0.2);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

/* Timetable */
.timetable-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.day-column {
    background: var(--card-bg);
    border-radius: 1rem;
    padding: 1rem;
    border: 1px solid var(--card-border);
}

.day-column h4 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 600;
    text-align: center;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--card-border);
}

/* Forms */
.form-card {
    max-width: 450px;
    margin: 4rem auto;
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    padding: 2.5rem;
    border-radius: 1.5rem;
    border: 1px solid var(--card-border);
    box-shadow: var(--glass-shadow);
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
}

.form-input {
    width: 100%;
    padding: 0.875rem;
    background: rgba(15, 23, 42, 0.5);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
}

/* Mobile */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .main-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
        padding: 1rem;
    }

    .user-header {
        flex-direction: column;
        text-align: center;
    }

    .user-header>div:last-child {
        margin-left: 0;
        width: 100%;
        justify-content: center;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .marks-grid {
        grid-template-columns: 1fr;
    }

    .timetable-grid {
        grid-template-columns: 1fr;
    }
}

/* Login */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.login-card {
    width: 100%;
    max-width: 420px;
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    padding: 3rem;
    border-radius: 1.5rem;
    border: 1px solid var(--card-border);
    box-shadow: var(--glass-shadow);
}

.alert {
    margin-bottom: 2rem;
    padding: 1rem;
    background: rgba(59, 130, 246, 0.15);
    border: 1px solid rgba(59, 130, 246, 0.3);
    border-radius: 0.75rem;
    color: var(--text-primary);
    backdrop-filter: blur(12px);
}

.header-actions {
    display: flex;
    gap: 0.75rem;
}

.user-actions {
    margin-left: auto;
    display: flex;
    gap: 0.5rem;
}

@media (max-width: 768px) {
    .user-actions {
        margin-left: 0;
        width: 100%;
        justify-content: center;
    }
}

.mark-note {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.empty-state {
    text-align: center;
    padding: 4rem 0;
    color: var(--text-secondary);
}

.empty-state p:last-child {
    font-size: 0.875rem;
    margin-top: 0.5rem;
}

.timetable-item {
    margin-bottom: 0.75rem;
    padding: 0.75rem;
    font-size: 0.9em;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--card-border);
    border-radius: 0.5rem;
}

.clashes-container {
    margin-top: 2rem;
    padding: 1.5rem;
    background: rgba(239, 68, 68, 0.15);
    border: 1px solid rgba(239, 68, 68, 0.3);
    border-radius: 1rem;
    color: var(--text-primary);
}

.clashes-container h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.clashes-container ul {
    list-style-type: none;
    padding: 0;
}

.clashes-container li {
    margin-bottom: 0.5rem;
    padding-left: 1.5rem;
    position: relative;
}

.clashes-container li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--danger);
}

.text-center {
    text-align: center;
}

.w-full {
    width: 100%;
}

.justify-center {
    justify-content: center;
}

.mb-4 {
    margin-bottom: 1rem;
}

.mb-8 {
    margin-bottom: 2rem;
}

.mt-2 {
    margin-top: 0.5rem;
}

.mt-4 {
    margin-top: 1rem;
}

.text-sm {
    font-size: 0.875rem;
}

.text-secondary {
    color: var(--text-secondary);
}

.divider {
    border: 0;
    border-top: 1px solid var(--card-border);
    margin: 2rem 0;
}

.nav-user {
    margin-right: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.main-header a {
    text-decoration: none;
    color: inherit;
}

.main-header nav {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}