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

        html, body {
            height: 100%;
            overflow-x: hidden;
        }

        body {
            font-family: 'Malgun Gothic', 'Apple SD Gothic Neo', 'Noto Sans KR', sans-serif;
            background-color: #f8f9fa;
            color: #333;
            line-height: 1.5;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        .container {
            width: 100%;
            max-width: 100vw;
            margin: 0 auto;
            background-color: white;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        /* 헤더 */
        .header {
            background-color: white;
            padding: 15px 20px;
            text-align: center;
            border-bottom: 1px solid #e9ecef;
            position: sticky;
            top: 0;
            z-index: 10;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }

        .header h1 {
            font-size: 18px;
            font-weight: 500;
            color: #333;
            letter-spacing: -0.5px;
        }

        /* 메인 콘텐츠 */
        .login-container {
            flex: 1;
            padding: 20px 16px;
            max-width: 100%;
        }

        .form-wrapper {
            max-width: 400px;
            margin: 0 auto;
            width: 100%;
        }

        .input-group {
            margin-bottom: 20px;
            position: relative;
        }

        .input-field {
            width: 100%;
            padding: 16px 0 12px 0;
            border: none;
            border-bottom: 1.5px solid #dee2e6;
            font-size: 16px;
            background-color: transparent;
            outline: none;
            transition: all 0.3s ease;
            color: #333;
            -webkit-appearance: none;
            -moz-appearance: none;
            appearance: none;
        }

        .input-field:focus {
            border-bottom-color: #e91e63;
            box-shadow: 0 1px 0 0 #e91e63;
        }

        .input-field::placeholder {
            color: #999;
            font-size: 16px;
            opacity: 1;
        }

        .input-hint {
            color: #6c757d;
            font-size: 12px;
            margin-top: 4px;
            margin-left: 2px;
        }

        /* 체크박스 */
        .checkbox-container {
            display: flex;
            align-items: flex-start;
            margin-bottom: 20px;
            padding: 12px 0;
            gap: 12px;
        }

        .checkbox {
            width: 20px;
            height: 20px;
            min-width: 20px;
            accent-color: #e91e63;
            cursor: pointer;
            margin-top: 1px;
        }

        .checkbox-label {
            color: #495057;
            font-size: 14px;
            cursor: pointer;
            flex: 1;
            line-height: 1.5;
            word-break: keep-all;
            -webkit-tap-highlight-color: transparent;
        }

        /* 버튼들 */
        .privacy-btn {
            width: 100%;
            background-color: transparent;
            color: #6c757d;
            border: 1px solid #dee2e6;
            padding: 14px 16px;
            font-size: 14px;
            border-radius: 25px;
            margin-bottom: 20px;
            cursor: pointer;
            transition: all 0.3s ease;
            -webkit-tap-highlight-color: transparent;
            touch-action: manipulation;
        }

        .privacy-btn:hover,
        .privacy-btn:active {
            background-color: #f8f9fa;
            border-color: #adb5bd;
            transform: translateY(-1px);
        }

        .login-btn {
            width: 100%;
            background: linear-gradient(135deg, #e91e63 0%, #ff4081 100%);
            color: white;
            border: none;
            padding: 16px;
            font-size: 16px;
            font-weight: 600;
            border-radius: 25px;
            margin-bottom: 12px;
            cursor: pointer;
            transition: all 0.3s ease;
            -webkit-tap-highlight-color: transparent;
            touch-action: manipulation;
            letter-spacing: 0.5px;
        }

        .login-btn:hover:not(:disabled) {
            background: linear-gradient(135deg, #d81b60 0%, #f50057 100%);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(233, 30, 99, 0.3);
        }

        .login-btn:active:not(:disabled) {
            transform: translateY(0);
        }

        .login-btn:disabled {
            background: linear-gradient(135deg, #adb5bd 0%, #6c757d 100%);
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
            opacity: 0.7;
        }

        .student-btn {
            width: 100%;
            background-color: #495057;
            color: white;
            border: none;
            padding: 16px;
            font-size: 14px;
            font-weight: 600;
            border-radius: 25px;
            margin-bottom: 30px;
            cursor: pointer;
            transition: all 0.3s ease;
            -webkit-tap-highlight-color: transparent;
            touch-action: manipulation;
        }

        .student-btn:hover,
        .student-btn:active {
            background-color: #343a40;
            transform: translateY(-1px);
        }

        /* 안내 텍스트 */
        .notice-text {
            text-align: center;
            color: #6c757d;
            font-size: 13px;
            line-height: 1.6;
            padding: 0 10px;
            word-break: keep-all;
        }

        /* 로딩 상태 */
        .loading {
            position: relative;
            pointer-events: none;
        }

        .loading::after {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            width: 20px;
            height: 20px;
            margin: -10px 0 0 -10px;
            border: 2px solid transparent;
            border-top: 2px solid white;
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

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

        /* 모바일 최적화 - 세밀한 반응형 */
        @media screen and (max-width: 480px) {
            .header {
                padding: 12px 16px;
            }
            
            .header h1 {
                font-size: 16px;
            }

            .login-container {
                padding: 16px 12px;
            }

            .input-field {
                font-size: 16px; /* iOS 줌 방지 */
                padding: 14px 0 10px 0;
            }

            .checkbox-container {
                gap: 10px;
            }

            .checkbox {
                width: 18px;
                height: 18px;
                min-width: 18px;
            }

            .privacy-btn {
                padding: 12px 14px;
                font-size: 13px;
            }

            .login-btn, .student-btn {
                padding: 14px;
                font-size: 15px;
            }

            .notice-text {
                font-size: 12px;
                padding: 0 5px;
            }
        }

        @media screen and (max-width: 360px) {
            .login-container {
                padding: 12px 8px;
            }
            
            .checkbox-label {
                font-size: 13px;
            }
            
            .input-hint {
                font-size: 11px;
            }
        }

        /* 가로 방향 (랜드스케이프) */
        @media screen and (orientation: landscape) and (max-height: 500px) {
            .header {
                padding: 8px 16px;
            }
            
            .login-container {
                padding: 12px 16px;
            }
            
            .input-group {
                margin-bottom: 15px;
            }
            
            .checkbox-container {
                margin-bottom: 15px;
                padding: 8px 0;
            }
            
            .privacy-btn {
                margin-bottom: 15px;
            }
            
            .student-btn {
                margin-bottom: 20px;
            }
        }

        /* 태블릿 */
        @media screen and (min-width: 481px) and (max-width: 768px) {
            .container {
                max-width: 500px;
                margin: 0 auto;
                box-shadow: 0 0 20px rgba(0,0,0,0.1);
            }
            
            .login-container {
                padding: 30px 24px;
            }
            
            .header h1 {
                font-size: 20px;
            }
        }

        /* 데스크톱 */
        @media screen and (min-width: 769px) {
            .container {
                max-width: 420px;
                margin: 20px auto;
                border-radius: 12px;
                overflow: hidden;
                box-shadow: 0 4px 30px rgba(0,0,0,0.15);
            }
            
            .header {
                border-radius: 12px 12px 0 0;
            }
            
            .login-container {
                padding: 40px 32px;
            }
        }

        /* 다크 모드 지원 */
        @media (prefers-color-scheme: dark) {
            body {
                background-color: #121212;
                color: #e0e0e0;
            }
            
            .container {
                background-color: #1e1e1e;
            }
            
            .header {
                background-color: #1e1e1e;
                border-bottom-color: #333;
            }
            
            .input-field {
                color: #e0e0e0;
                border-bottom-color: #444;
            }
            
            .input-field:focus {
                border-bottom-color: #e91e63;
            }
        }

        /* 터치 디바이스 최적화 */
        @media (hover: none) and (pointer: coarse) {
            .privacy-btn:hover,
            .login-btn:hover,
            .student-btn:hover {
                transform: none;
            }
            
            .privacy-btn:active,
            .login-btn:active:not(:disabled),
            .student-btn:active {
                transform: scale(0.98);
            }
        }