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

:root {
    --primary: #6C3CE1;
    --primary-dark: #5A2DCA;
    --primary-light: #8B6BE8;
    --secondary: #FF6B6B;
    --success: #2ECC71;
    --warning: #F39C12;
    --dark: #2D2D3F;
    --gray: #6B6B80;
    --light-gray: #F0F0F5;
    --white: #FFFFFF;
    --shadow: 0 4px 20px rgba(108, 60, 225, 0.15);
    --radius: 16px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #F8F7FF 0%, #EDE9FF 100%);
    min-height: 100vh;
    color: var(--dark);
    padding: 20px;
}

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

/* Header */
.header {
    background: var(--white);
    padding: 20px 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 15px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    font-size: 28px;
}

.logo h1 {
    font-size: 24px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-info {
    font-size: 14px;
    color: var(--gray);
    background: var(--light-gray);
    padding: 6px 16px;
    border-radius: 20px;
}

/* Sections */
.section {
    background: var(--white);
    border-radius: var(--radius);
    padding: 25px 30px;
    margin-bottom: 25px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.section:hover {
    box-shadow: 0 6px 30px rgba(108, 60, 225, 0.2);
}

.section h2 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--dark);
}

/* Forms */
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 15px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-group label {
    font-size: 14px;
    font-weight: 600;
    color: var(--gray);
}

.form-group select,
.form-group input {
    padding: 12px 16px;
    border: 2px solid var(--light-gray);
    border-radius: 12px;
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
    background: var(--light-gray);
    color: var(--dark);
}

.form-group select:focus,
.form-group input:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--white);
    box-shadow: 0 0 0 4px rgba(108, 60, 225, 0.1);
}

.form-group input::placeholder {
    color: #B0B0C0;
}

/* Buttons */
.btn {
    padding: 12px 28px;
    border: none;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: var(--white);
    width: 100%;
    justify-content: center;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(108, 60, 225, 0.4);
}

.btn-secondary {
    background: var(--primary-light);
    color: var(--white);
}

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

.btn-outline {
    background: transparent;
    color: var(--gray);
    border: 2px solid var(--light-gray);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.filter-form .btn {
    margin-right: 10px;
    margin-bottom: 10px;
}

/* List */
.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 10px;
}

.count-badge {
    background: var(--primary);
    color: var(--white);
    padding: 4px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
}

.exchange-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.exchange-card {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    background: var(--light-gray);
    border-radius: 12px;
    transition: var(--transition);
    flex-wrap: wrap;
    gap: 12px;
    border: 2px solid transparent;
}

.exchange-card:hover {
    border-color: var(--primary);
    background: var(--white);
    transform: translateX(4px);
}

.card-info {
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.card-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 14px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
}

.card-badge.have {
    background: #E8F5E9;
    color: #2E7D32;
}

.card-badge.need {
    background: #FCE4EC;
    color: #C62828;
}

.card-arrow {
    color: var(--gray);
    font-weight: 700;
    font-size: 20px;
}

.card-code {
    font-family: 'Courier New', monospace;
    background: var(--white);
    padding: 4px 12px;
    border-radius: 8px;
    font-size: 13px;
    color: var(--primary);
    font-weight: 600;
    border: 1px dashed var(--primary-light);
}

.card-time {
    font-size: 12px;
    color: var(--gray);
}

.copy-btn {
    background: var(--white);
    border: none;
    padding: 6px 14px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 600;
    color: var(--primary);
    transition: var(--transition);
}

.copy-btn:hover {
    background: var(--primary);
    color: var(--white);
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--gray);
}

.empty-state .empty-icon {
    font-size: 48px;
    display: block;
    margin-bottom: 16px;
}

.empty-state p {
    font-size: 16px;
}

/* Loading Spinner */
.loading-spinner {
    text-align: center;
    padding: 40px 20px;
}

.spinner {
    border: 4px solid var(--light-gray);
    border-top: 4px solid var(--primary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 16px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Footer */
.footer {
    text-align: center;
    padding: 20px;
    color: var(--gray);
    font-size: 14px;
}

.footer .note {
    font-size: 12px;
    margin-top: 4px;
    color: #B0B0C0;
}

/* Responsive */
@media (max-width: 768px) {
    body {
        padding: 12px;
    }
    
    .header {
        padding: 15px 20px;
        flex-direction: column;
        align-items: flex-start;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: 18px 16px;
    }
    
    .exchange-card {
        flex-direction: column;
        align-items: stretch;
    }
    
    .card-info {
        flex-wrap: wrap;
    }
    
    .filter-form .btn {
        width: 100%;
        justify-content: center;
        margin-right: 0;
    }
}

/* Toast notification */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--dark);
    color: var(--white);
    padding: 14px 28px;
    border-radius: 12px;
    font-weight: 500;
    box-shadow: 0 8px 30px rgba(0,0,0,0.2);
    opacity: 0;
    transition: all 0.4s ease;
    z-index: 1000;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

.toast.success {
    background: var(--success);
}

.toast.error {
    background: var(--secondary);
}
/* Thêm vào style.css */

/* Textarea styles */
.form-group textarea {
    padding: 12px 16px;
    border: 2px solid var(--light-gray);
    border-radius: 12px;
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
    background: var(--light-gray);
    color: var(--dark);
    resize: vertical;
    min-height: 80px;
    width: 100%;
}

.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--white);
    box-shadow: 0 0 0 4px rgba(108, 60, 225, 0.1);
}

/* Auto-extract highlight */
.extract-success {
    border-color: var(--success) !important;
    background: #E8F5E9 !important;
}

.extract-error {
    border-color: var(--secondary) !important;
    background: #FFEBEE !important;
}

/* Toggle mode hint */
.mode-hint {
    text-align: center;
    padding: 10px;
    background: var(--light-gray);
    border-radius: 8px;
    margin: 10px 0;
    color: var(--gray);
    font-size: 13px;
}