@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');
        
        * {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
        }

        body {
            background: #ffffff;
            overflow-x: hidden;
        }

        .gradient-text {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .card-swipe {
            position: absolute;
            width: 90%;
            max-width: 400px;
            height: 550px;
            left: 50%;
            top: 50%;
            transform: translate(-50%, -50%);
            transition: transform 0.3s ease, opacity 0.3s ease;
            cursor: grab;
        }

        .card-swipe:active {
            cursor: grabbing;
        }

        .nav-blur {
            backdrop-filter: blur(12px);
            background: rgba(255, 255, 255, 0.9);
            border-bottom: 1px solid rgba(0, 0, 0, 0.05);
        }

        .btn-primary {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            transition: all 0.3s ease;
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(102, 126, 234, 0.3);
        }

        .feature-card {
            transition: all 0.3s ease;
            border: 1px solid #e5e7eb;
        }

        .feature-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
            border-color: #667eea;
        }

        .timetable-grid {
            display: grid;
            grid-template-columns: 80px repeat(5, 1fr);
            gap: 2px;
            background: #e5e7eb;
            border-radius: 12px;
            overflow: hidden;
        }

        .time-slot {
            background: white;
            padding: 12px 8px;
            min-height: 60px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 13px;
            cursor: pointer;
            transition: all 0.2s;
        }

        .time-slot:hover {
            background: #f3f4f6;
        }

        .time-slot.header {
            font-weight: 700;
            background: #f9fafb;
            cursor: default;
        }

        .time-slot.time-label {
            background: #f9fafb;
            font-weight: 600;
            color: #6b7280;
            cursor: default;
        }

        .time-slot.busy {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            font-weight: 600;
            cursor: pointer;
        }

        .time-slot.busy:hover {
            opacity: 0.9;
        }

        .modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.5);
            backdrop-filter: blur(4px);
            z-index: 1000;
            animation: fadeIn 0.2s ease;
        }

        .modal.active {
            display: flex;
            align-items: center;
            justify-content: center;
        }

        @keyframes fadeIn {
            from { opacity: 0; }
            to { opacity: 1; }
        }

        @keyframes slideUp {
            from { transform: translateY(20px); opacity: 0; }
            to { transform: translateY(0); opacity: 1; }
        }

        .slide-up {
            animation: slideUp 0.3s ease;
        }

        .swipe-indicator {
            position: absolute;
            top: 50%;
            font-size: 48px;
            font-weight: bold;
            opacity: 0;
            transition: opacity 0.2s;
            pointer-events: none;
            transform: translateY(-50%);
        }

        .swipe-left { left: 20px; color: #ef4444; }
        .swipe-right { right: 20px; color: #10b981; }

        .profile-card {
            background: white;
            border-radius: 24px;
            overflow: hidden;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
        }

        .page {
            display: none;
        }

        .page.active {
            display: block;
        }

        .match-badge {
            animation: pulse 2s infinite;
        }

        @keyframes pulse {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.05); }
        }

        .upload-method-btn {
            transition: all 0.2s ease;
        }

        .upload-method-btn.active {
            background: #eef2ff;
            border-color: #667eea;
            color: #667eea;
        }

        /* Temporary chat UI block for Firebase testing */
        #chat-section {
            width: 400px;
            margin: 20px auto;
            border: 1px solid #ccc;
            border-radius: 10px;
            padding: 10px;
            background: #f9f9f9;
            font-family: sans-serif;
        }

        #chat-section .chat-box {
            height: 300px;
            overflow-y: auto;
            border: 1px solid #ddd;
            border-radius: 6px;
            padding: 10px;
            background: #fff;
        }

        #chat-section .chat-input {
            margin-top: 10px;
            display: flex;
            gap: 5px;
        }

        #chat-section .chat-input input {
            flex: 1;
            padding: 8px;
            border: 1px solid #ccc;
            border-radius: 6px;
        }

        #chat-section .chat-input button {
            padding: 8px 14px;
            border: none;
            border-radius: 6px;
            background: #007bff;
            color: white;
            cursor: pointer;
        }

        #chat-section .chat-input button:hover {
            background: #0056b3;
        }

        #chat-section .message {
            margin-bottom: 8px;
            padding: 6px 8px;
            border-radius: 6px;
            max-width: 70%;
        }

        #chat-section .mine {
            background: #dcf8c6;
            align-self: flex-end;
        }

        #chat-section .theirs {
            background: #e9ecef;
            align-self: flex-start;
        }