:root {
            /* 浅色主题变量 */
            --bg: #f0f4f8;
            --card-bg: #ffffff;
            --text: #1a202c;
            --text-secondary: #5a6c7d;
            --text-muted: #94a3b8;
            --border: #e2e8f0;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
            --shadow: 0 4px 20px rgba(0, 0, 0, 0.07), 0 1px 4px rgba(0, 0, 0, 0.05);
            --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.12), 0 4px 16px rgba(0, 0, 0, 0.06);
            --radius: 16px;
            --radius-sm: 10px;
            --radius-xs: 6px;
            --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            --today-bg: #fff0e6;
            --today-border: #ff8c42;
            --accent: #ff6b6b;
            --accent-hover: #e55a5a;
            --accent-light: #fff0ed;
            --month-nav-bg: #f8fafc;
            --btn-today-bg: #fff;
            --btn-today-text: #ff8c42;
            --modal-bg: #ffffff;
            --friend-item-bg: #fafbfc;
            --friend-item-hover-bg: #f1f5f9;
            --mini-month-bg: #f8fafc;
            --search-bg: #f8fafc;
            --panel-bg: #ffffff;
            --friend-card-bg: #fafbfc;
            --chart-grid: #e8edf3;
            --chart-bar-light: #c4d6e8;
            --chart-bar-dark: #a0b8d0;
            --chart-text: #94a3b8;
            --chart-highlight: #ff8c42;
            --chart-highlight-text: #d46b2a;
            --toast-bg: #1a202c;
            --toast-text: #fff;
        }

        body.dark-theme {
            --bg: #0f172a;
            --card-bg: #1e293b;
            --text: #f1f5f9;
            --text-secondary: #cbd5e1;
            --text-muted: #94a3b8;
            --border: #334155;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
            --shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
            --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.3);
            --today-bg: #332018;
            --today-border: #ff8c42;
            --month-nav-bg: #1e293b;
            --btn-today-bg: #1e293b;
            --btn-today-text: #ff8c42;
            --modal-bg: #1e293b;
            --friend-item-bg: #1e293b;
            --friend-item-hover-bg: #263348;
            --mini-month-bg: #1e293b;
            --search-bg: #1e293b;
            --panel-bg: #1e293b;
            --friend-card-bg: #1e293b;
            --chart-grid: #334155;
            --chart-bar-light: #475569;
            --chart-bar-dark: #64748b;
            --chart-text: #94a3b8;
            --toast-bg: #f1f5f9;
            --toast-text: #0f172a;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
            background: var(--bg);
            background-attachment: fixed;
            min-height: 100vh;
            color: var(--text);
            line-height: 1.5;
            -webkit-font-smoothing: antialiased;
            transition: background 0.3s, color 0.3s;
        }
		
		/* 登录界面 */
        .login-overlay {
            position: fixed; top:0; left:0; right:0; bottom:0;
            background: var(--bg); display:flex; align-items:center; justify-content:center;
            z-index:1000; flex-direction:column; gap:16px;
        }
        .login-card {
            background: var(--card-bg); border-radius: var(--radius); padding: 40px 30px;
            box-shadow: var(--shadow-lg); text-align:center; max-width:360px; width:90%;
        }
        .btn-google {
            background: #fff; color: #444; border: 1px solid #ddd; padding: 12px 24px;
            border-radius: 25px; font-weight:600; cursor:pointer; display:inline-flex;
            align-items:center; gap:8px; transition:0.2s; font-size:1rem;
        }
        .btn-google:hover { box-shadow: 0 2px 8px rgba(0,0,0,0.1); background:#f8f8f8; }

        .app-header {
            background: var(--card-bg);
            border-bottom: 1px solid var(--border);
            padding: 10px 20px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 8px;
            box-shadow: var(--shadow-sm);
            position: sticky;
            top: 0;
            z-index: 100;
            backdrop-filter: blur(10px);
            transition: background 0.3s, border-color 0.3s;
        }
        .app-logo {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--text);
        }
        .app-logo .icon {
            width: 34px;
            height: 34px;
            border-radius: 10px;
            background: linear-gradient(135deg, #ff8c42, #ff6b6b);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            box-shadow: 0 4px 12px rgba(255, 107, 107, 0.3);
        }
        .header-right {
            display: flex;
            align-items: center;
            gap: 8px;
            flex-wrap: wrap;
        }
        .year-nav {
            display: flex;
            align-items: center;
            gap: 4px;
            background: var(--month-nav-bg);
            border-radius: 25px;
            padding: 4px 6px;
            border: 1px solid var(--border);
        }
        .year-nav button {
            width: 30px;
            height: 30px;
            border-radius: 50%;
            border: none;
            background: transparent;
            cursor: pointer;
            font-size: 1rem;
            color: var(--text-secondary);
            transition: 0.2s;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .year-nav button:hover {
            background: var(--border);
            color: var(--text);
        }
        .year-display {
            font-weight: 700;
            font-size: 0.95rem;
            padding: 0 4px;
            min-width: 40px;
            text-align: center;
            color: var(--text);
        }
        .btn-header {
            padding: 6px 12px;
            border-radius: 20px;
            border: 1.5px solid var(--border);
            background: var(--card-bg);
            color: var(--text-secondary);
            cursor: pointer;
            font-weight: 600;
            font-size: 0.8rem;
            transition: 0.2s;
            white-space: nowrap;
            display: flex;
            align-items: center;
            gap: 4px;
        }
        .btn-header:hover {
            background: var(--friend-item-hover-bg);
            border-color: var(--text-muted);
        }
        .btn-today {
            border-color: var(--today-border);
            color: var(--btn-today-text);
            background: var(--btn-today-bg);
        }
        .btn-add-friend {
            background: linear-gradient(135deg, #ff8c42, #ff6b6b);
            color: #fff;
            border: none;
            box-shadow: 0 4px 14px rgba(255, 107, 107, 0.35);
        }
        .today-birthday-alert {
            background: #fffbf0;
            border: 1.5px solid #ffc940;
            border-radius: 20px;
            padding: 5px 12px;
            font-size: 0.8rem;
            font-weight: 600;
            color: #b7791f;
            cursor: pointer;
            white-space: nowrap;
            animation: pulse 2s infinite;
        }
        .no-today-birthday {
            font-size: 0.8rem;
            color: var(--text-muted);
        }
        @keyframes pulse {
            0%,
            100% {
                box-shadow: 0 0 0 0 rgba(255, 201, 64, 0.5);
            }
            50% {
                box-shadow: 0 0 0 8px rgba(255, 201, 64, 0);
            }
        }

        .main-container {
            display: grid;
            grid-template-columns: 1fr 380px;
            gap: 20px;
            padding: 20px 24px;
            max-width: 1300px;
            margin: 0 auto;
            align-items: start;
        }
        .card {
            background: var(--card-bg);
            border-radius: var(--radius);
            padding: 18px;
            box-shadow: var(--shadow);
            border: 1px solid var(--border);
            transition: background 0.3s, border-color 0.3s;
        }
        .calendar-section {
            display: flex;
            flex-direction: column;
            gap: 16px;
        }
        .month-navigator {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 10px;
        }
        .month-navigator button {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            border: 1.5px solid var(--border);
            background: var(--card-bg);
            cursor: pointer;
            font-size: 1.1rem;
            color: var(--text-secondary);
            transition: 0.2s;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .month-title {
            font-size: 1.3rem;
            font-weight: 700;
            text-align: center;
            min-width: 120px;
            color: var(--text);
        }
        .calendar-grid {
            display: grid;
            grid-template-columns: repeat(7, 1fr);
            gap: 3px;
        }
        .day-header {
            text-align: center;
            font-weight: 700;
            font-size: 0.75rem;
            color: var(--text-muted);
            padding: 6px 0;
        }
        .day-cell {
            aspect-ratio: 1/1;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            border-radius: 6px;
            cursor: pointer;
            transition: 0.2s;
            font-weight: 500;
            font-size: 0.85rem;
            border: 2px solid transparent;
            color: var(--text);
            position: relative;
        }
        .day-cell:hover {
            background: var(--friend-item-hover-bg);
            border-color: var(--border);
        }
        .day-cell.other-month {
            color: #4a5568;
            opacity: 0.4;
            pointer-events: none;
        }
        .day-cell.today {
            background: var(--today-bg) !important;
            border-color: var(--today-border) !important;
            font-weight: 800;
            color: #d46b2a;
        }
        .birthday-dots {
            display: flex;
            gap: 2px;
            justify-content: center;
            margin-top: 2px;
        }
        .birthday-dot {
            width: 5px;
            height: 5px;
            border-radius: 50%;
        }
        .side-panel {
            display: flex;
            flex-direction: column;
            gap: 16px;
            position: sticky;
            top: 90px;
        }
        .mini-year-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 6px;
        }
        .mini-month {
            aspect-ratio: 1.4/1;
            border-radius: 6px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            font-size: 0.75rem;
            font-weight: 600;
            border: 2px solid transparent;
            background: var(--mini-month-bg);
            color: var(--text-secondary);
            transition: 0.2s;
        }
        .mini-month.active {
            border-color: #ff8c42 !important;
            color: #d46b2a;
            background: var(--card-bg);
        }
        .chart-container {
            width: 100%;
            height: 160px;
        }
        .friend-list {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 6px;
            max-height: 280px;
            overflow-y: auto;
        }
        .friend-item {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 10px 12px;
            border-radius: 8px;
            cursor: pointer;
            border: 1.5px solid transparent;
            background: var(--friend-item-bg);
            transition: 0.2s;
        }
        .friend-item:hover {
            background: var(--friend-item-hover-bg);
            border-color: var(--border);
        }
        .friend-avatar {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            font-size: 0.8rem;
            color: #fff;
            flex-shrink: 0;
        }
        .friend-info {
            flex: 1;
        }
        .friend-name {
            font-weight: 600;
            font-size: 0.9rem;
        }
        .modal-overlay {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.5);
            z-index: 200;
            display: flex;
            align-items: center;
            justify-content: center;
            backdrop-filter: blur(4px);
        }
        .modal-dialog,
        .day-friends-panel {
            background: var(--modal-bg);
            border-radius: 16px;
            padding: 24px;
            width: 90%;
            max-width: 400px;
            box-shadow: var(--shadow-lg);
            position: relative;
        }
        .form-group {
            margin-bottom: 12px;
        }
        .form-group label {
            display: block;
            font-weight: 600;
            font-size: 0.8rem;
            margin-bottom: 4px;
            color: var(--text-secondary);
        }
        .form-group input,
        .form-group select,
        .form-group textarea {
            width: 100%;
            padding: 8px 12px;
            border-radius: 8px;
            border: 1.5px solid var(--border);
            background: var(--search-bg);
            color: var(--text);
            font-family: inherit;
        }
        .btn {
            padding: 8px 16px;
            border-radius: 20px;
            border: none;
            cursor: pointer;
            font-weight: 600;
            font-size: 0.85rem;
            transition: 0.2s;
        }
        .btn-primary {
            background: linear-gradient(135deg, #ff8c42, #ff6b6b);
            color: #fff;
        }
        .btn-secondary {
            background: var(--friend-item-hover-bg);
            color: var(--text);
        }
        .friend-carousel {
            display: flex;
            align-items: center;
            gap: 10px;
            margin: 16px 0;
        }
        .carousel-btn {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            border: 1px solid var(--border);
            background: var(--card-bg);
            cursor: pointer;
            color: var(--text);
        }
        .friend-card {
            background: var(--friend-card-bg);
            padding: 16px;
            border-radius: 12px;
            flex: 1;
            text-align: center;
            box-shadow: var(--shadow-sm);
        }
        .toast {
            position: fixed;
            bottom: 30px;
            left: 50%;
            transform: translateX(-50%);
            background: var(--toast-bg);
            color: var(--toast-text);
            padding: 10px 24px;
            border-radius: 25px;
            font-weight: 600;
            z-index: 300;
            animation: toastIn 0.3s ease, toastOut 0.3s ease 2s forwards;
        }
        @keyframes toastIn {
            from {
                opacity: 0;
                transform: translateX(-50%) translateY(10px);
            }
            to {
                opacity: 1;
                transform: translateX(-50%) translateY(0);
            }
        }
        @keyframes toastOut {
            to {
                opacity: 0;
                transform: translateX(-50%) translateY(10px);
            }
        }
        @media (max-width: 960px) {
            .main-container {
                grid-template-columns: 1fr;
                padding: 12px;
            }
            .side-panel {
                position: static;
            }
        }