/* Modern UI Design System - 2025 */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    /* Color Palette - Indigo/Violet Theme */
    --primary-50: #eef2ff;
    --primary-100: #e0e7ff;
    --primary-500: #6366f1;
    --primary-600: #4f46e5;
    --primary-700: #4338ca;
    
    --secondary-50: #f8fafc;
    --secondary-100: #f1f5f9;
    --secondary-200: #e2e8f0;
    --secondary-500: #64748b;
    --secondary-800: #1e293b;
    --secondary-900: #0f172a;

    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;

    /* Semantic Colors */
    --bg-body: #f8fafc;
    --bg-card: #ffffff;
    --text-main: var(--secondary-800);
    --text-muted: var(--secondary-500);
    --border-color: var(--secondary-200);

    /* Effects */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--secondary-900);
    font-weight: 700;
    letter-spacing: -0.025em;
}

/* Buttons */
.ui-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    gap: 0.5rem;
}

.ui-btn:active {
    transform: scale(0.98);
}

.ui-btn-primary {
    background: linear-gradient(135deg, var(--primary-600), var(--primary-700));
    color: white;
    box-shadow: 0 4px 6px -1px rgba(79, 70, 229, 0.2);
}

.ui-btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
    box-shadow: 0 6px 8px -1px rgba(79, 70, 229, 0.3);
}

.ui-btn-secondary {
    background: white;
    border-color: var(--secondary-200);
    color: var(--secondary-800);
}

.ui-btn-secondary:hover {
    background: var(--secondary-50);
    border-color: var(--secondary-300);
}

.ui-btn-danger {
    background: var(--error);
    color: white;
}

.ui-btn-danger:hover {
    background: #dc2626;
}

.ui-btn-success {
    background: var(--success);
    color: white;
}

/* Inputs */
.ui-input {
    width: 100%;
    padding: 0.625rem 1rem;
    border: 1px solid var(--secondary-200);
    border-radius: var(--radius-md);
    background-color: white;
    color: var(--text-main);
    font-size: 0.875rem;
    transition: var(--transition);
}

.ui-input:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px var(--primary-100);
}

/* Custom Select / Dropdown */
.ui-select-wrapper {
    position: relative;
    width: 100%;
}

.ui-select-trigger {
    width: 100%;
    padding: 0.625rem 2.5rem 0.625rem 1rem;
    border: 1px solid var(--secondary-200);
    border-radius: var(--radius-md);
    background-color: white;
    color: var(--text-main);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: space-between;
    user-select: none;
}

.ui-select-trigger::after {
    content: '';
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 5px solid var(--secondary-500);
    transition: transform 0.2s;
}

.ui-select-wrapper.open .ui-select-trigger::after {
    transform: translateY(-50%) rotate(180deg);
}

.ui-select-trigger:hover {
    border-color: var(--secondary-300);
}

.ui-select-wrapper.open .ui-select-trigger,
.ui-select-trigger:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px var(--primary-100);
}

.ui-select-trigger .placeholder {
    color: var(--text-muted);
}

.ui-select-dropdown {
    position: absolute;
    top: calc(100% + 4px);
    left: 0;
    right: 0;
    background: white;
    border: 1px solid var(--secondary-200);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    max-height: 240px;
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.ui-select-wrapper.open .ui-select-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.ui-select-option {
    padding: 0.625rem 1rem;
    cursor: pointer;
    transition: background 0.15s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.ui-select-option:hover {
    background: var(--secondary-50);
}

.ui-select-option.selected {
    background: var(--primary-50);
    color: var(--primary-700);
    font-weight: 500;
}

.ui-select-option.selected::before {
    content: '✓';
    font-size: 0.75rem;
    color: var(--primary-600);
}

.ui-select-option:first-child {
    border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.ui-select-option:last-child {
    border-radius: 0 0 var(--radius-md) var(--radius-md);
}

/* 隐藏原生 select */
.ui-select-wrapper select.ui-select-native {
    position: absolute;
    opacity: 0;
    pointer-events: none;
    width: 100%;
    height: 100%;
}

/* 兼容旧的 select.ui-input 样式 */
select.ui-input,
select.ui-select {
    width: 100%;
    padding: 0.625rem 2.5rem 0.625rem 1rem;
    border: 1px solid var(--secondary-200);
    border-radius: var(--radius-md);
    background-color: white;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 1rem;
    color: var(--text-main);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

select.ui-input:focus,
select.ui-select:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px var(--primary-100);
}

select.ui-input:hover,
select.ui-select:hover {
    border-color: var(--secondary-300);
}

/* Cards */
.ui-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--secondary-100);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
}

/* Notifications */
#notification-container {
    position: fixed;
    top: 1.5rem;
    right: 1.5rem;
    z-index: 50;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.notification {
    min-width: 320px;
    padding: 1rem;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid transparent;
    transform: translateX(100%);
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.notification.show {
    transform: translateX(0);
    opacity: 1;
}

.notification-success { border-left-color: var(--success); }
.notification-error { border-left-color: var(--error); }
.notification-warning { border-left-color: var(--warning); }
.notification-info { border-left-color: var(--info); }

.notification-icon {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    color: white;
}

.notification-success .notification-icon { background: var(--success); }
.notification-error .notification-icon { background: var(--error); }
.notification-warning .notification-icon { background: var(--warning); }
.notification-info .notification-icon { background: var(--info); }

.notification-message {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--secondary-800);
}

/* Modal */
.ui-modal {
    position: fixed;
    inset: 0;
    z-index: 40;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
}

.ui-modal.show {
    opacity: 1;
    pointer-events: auto;
}

.ui-modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(15, 23, 42, 0.4);
    backdrop-filter: blur(4px);
}

.ui-modal-content {
    position: relative;
    background: white;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    padding: 1.5rem;
    transform: scale(0.95);
    transition: transform 0.2s;
    overflow-y: auto;
    overflow-x: hidden;
}

.ui-modal.show .ui-modal-content {
    transform: scale(1);
}

.ui-modal-content h3 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
}

.ui-modal-actions {
    margin-top: 1.5rem;
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
}

/* Utilities */
.text-sm { font-size: 0.875rem; }
.text-muted { color: var(--text-muted); }
.font-medium { font-weight: 500; }
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 0.5rem; }
.gap-4 { gap: 1rem; }
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }