:root {
    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --card-bg: rgba(255, 255, 255, 0.4);
    --card-border: rgba(255, 255, 255, 0.3);
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --danger-color: #e53e3e;
    --warning-color: #ecc94b;
    --success-color: #48bb78;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-gradient: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);
        --card-bg: rgba(255, 255, 255, 0.05);
        --card-border: rgba(255, 255, 255, 0.1);
        --text-primary: #f7fafc;
        --text-secondary: #e2e8f0;
    }
}

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

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: var(--bg-gradient);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 2rem;
}

.app-wrapper { width: 100%; max-width: 900px; }

.header { text-align: center; margin-bottom: 2rem; }

.logo {
    font-size: 2.5rem; font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.subtitle { font-weight: 500; color: var(--text-secondary); margin-bottom: 1rem; }

.login-bar {
    display: inline-flex; align-items: center; gap: 10px;
    padding: 10px 20px !important; border-radius: 12px !important;
    font-size: 0.9rem;
}

.login-bar select {
    padding: 6px 10px; border-radius: 8px;
    border: 1px solid var(--card-border);
    background: rgba(255,255,255,0.6); font-family: inherit;
}

.glass-tabs { display: flex; gap: 10px; margin-bottom: 2rem; justify-content: center; flex-wrap: wrap; }

.tab-btn {
    background: var(--card-bg); border: 1px solid var(--card-border);
    backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    padding: 12px 24px; border-radius: 12px;
    color: var(--text-primary); font-weight: 600;
    cursor: pointer; transition: all 0.3s ease;
}

.tab-btn:hover { transform: translateY(-2px); box-shadow: 0 4px 15px rgba(0,0,0,0.1); }

.tab-btn.active {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white; border: none;
    box-shadow: 0 4px 15px rgba(118,75,162,0.4);
}

.view-section { display: none; animation: fadeIn 0.4s ease forwards; }
.view-section.active { display: block; }

.glass-card {
    background: var(--card-bg); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--card-border); border-radius: 20px;
    padding: 2rem; box-shadow: 0 8px 32px 0 rgba(31,38,135,0.15);
}

.glass-card h2 {
    margin-bottom: 1.5rem; border-bottom: 2px solid var(--card-border); padding-bottom: 0.5rem;
}

.form-group { margin-bottom: 1.5rem; }
.form-row { display: flex; gap: 1rem; }
.form-row .form-group { flex: 1; }

label { display: block; font-weight: 600; margin-bottom: 0.5rem; font-size: 0.95rem; }

input, select {
    width: 100%; padding: 12px; border-radius: 10px;
    border: 1px solid var(--card-border);
    background: rgba(255,255,255,0.6); color: #1a202c;
    font-family: inherit; transition: box-shadow 0.2s;
}

input:focus, select:focus { outline: none; box-shadow: 0 0 0 3px rgba(102,126,234,0.5); }

.submit-btn {
    width: 100%; padding: 14px; border-radius: 10px; border: none;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white; font-weight: 700; font-size: 1.1rem;
    cursor: pointer; transition: all 0.3s; margin-top: 1rem;
}

.submit-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(118,75,162,0.5); }

/* Balance Grid */
.balance-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 1rem; margin-bottom: 2rem; }

.balance-card {
    text-align: center; padding: 1.5rem; border-radius: 15px;
    background: linear-gradient(135deg, rgba(102,126,234,0.15), rgba(118,75,162,0.15));
    border: 1px solid var(--card-border);
}

.balance-card h4 { margin-bottom: 0.5rem; color: var(--text-secondary); }

.balance-days { font-size: 2rem; font-weight: 800; color: var(--secondary-color); }
.balance-days .unit { font-size: 0.9rem; }

.progress-bar {
    height: 6px; background: rgba(0,0,0,0.1); border-radius: 3px;
    margin: 0.5rem 0; overflow: hidden;
}

.progress-fill {
    height: 100%; border-radius: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    transition: width 0.6s ease;
}

.balance-card small { color: var(--text-secondary); font-size: 0.8rem; }

/* History Items */
.history-list { margin-top: 1rem; }
.history-list h3 { margin-bottom: 1rem; }
.history-list ul { list-style: none; }

.history-item {
    background: var(--card-bg); border: 1px solid var(--card-border);
    padding: 1.2rem; border-radius: 12px; margin-bottom: 0.8rem;
    display: flex; justify-content: space-between; align-items: center;
    transition: transform 0.2s;
}

.history-item:hover { transform: translateX(5px); }

.history-details strong { display: block; font-size: 1rem; margin-bottom: 0.2rem; }
.history-details span { font-size: 0.85rem; color: var(--text-secondary); }

/* Status Badges */
.status-badge { padding: 6px 12px; border-radius: 20px; font-size: 0.8rem; font-weight: 600; white-space: nowrap; }
.pending { background: rgba(236,201,75,0.2); color: #b7791f; }
.approved { background: rgba(72,187,120,0.2); color: #276749; }
.returned { background: rgba(237,137,54,0.2); color: #9c4221; }
.rejected { background: rgba(229,62,62,0.2); color: #9b2c2c; }
.requires-mid { background: rgba(102,126,234,0.2); color: var(--primary-color); }
.badge { background: var(--danger-color); color: white; padding: 2px 8px; border-radius: 10px; font-size: 0.75rem; margin-left: 10px; }

/* Approval Cards */
.approval-card {
    background: var(--card-bg); border: 1px solid var(--card-border);
    padding: 1.5rem; border-radius: 12px; margin-bottom: 1rem;
    transition: transform 0.2s;
}

.approval-card:hover { transform: translateX(5px); }

.approval-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 0.8rem; flex-wrap: wrap; gap: 8px; }
.approval-desc { margin-bottom: 1rem; line-height: 1.6; }

.approval-actions { display: flex; gap: 8px; flex-wrap: wrap; }

.approval-actions button {
    padding: 8px 16px; border: none; border-radius: 8px;
    font-weight: 600; cursor: pointer; color: white; transition: transform 0.2s;
}
.approval-actions button:hover { transform: scale(1.05); }

.btn-approve { background: var(--success-color); }
.btn-return { background: var(--warning-color); color: #744210 !important; }
.btn-reject { background: var(--danger-color); }

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

@media (max-width: 600px) {
    .form-row { flex-direction: column; }
    .history-item { flex-direction: column; align-items: flex-start; gap: 8px; }
    .approval-header { flex-direction: column; }
}