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

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #1E2229; /* Midnight Charcoal */
    position: relative;
    overflow: hidden;
}

/* 배경 장식 원 */
body::before {
    content: "";
    position: absolute;
    top: -120px;
    right: -120px;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.05);
}

body::after {
    content: "";
    position: absolute;
    bottom: -80px;
    left: -80px;
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.03);
}

.login-wrapper {
    width: 100%;
    max-width: 420px;
    padding: 20px;
    position: relative;
    z-index: 1;
}

.login-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: 16px;
    padding: 48px 40px;
    box-shadow: 
        0 20px 60px rgba(0, 0, 0, 0.3),
        0 0 0 1px rgba(255, 255, 255, 0.1);
    animation: slideUp 0.6s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 로고 영역 */
.login-logo {
    text-align: center;
    margin-bottom: 36px;
}

.login-logo h1 {
    font-size: 28px;
    font-weight: 800;
    color: #1e293b; /* Ink Black */
    letter-spacing: 2px;
    margin-bottom: 6px;
}

.login-logo p {
    font-size: 13px;
    color: #8895a7;
    font-weight: 400;
    letter-spacing: 1px;
}

/* 폼 그룹 */
.form-group {
    margin-bottom: 22px;
    position: relative;
}

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: #4a5568;
    margin-bottom: 8px;
}

.form-group input {
    width: 100%;
    padding: 14px 16px;
    border: 1.5px solid #e2e8f0;
    border-radius: 10px;
    font-size: 14px;
    font-family: 'Inter', sans-serif;
    color: #2d3748;
    background: #f8fafc;
    transition: all 0.3s ease;
    outline: none;
}

.form-group input::placeholder {
    color: #a0aec0;
}

.form-group input:focus {
    border-color: #00A3E0; /* Cyan Blue */
    background: #fff;
    box-shadow: 0 0 0 3px rgba(0, 163, 224, 0.12);
}

/* 에러 상태 */
.form-group input.error {
    border-color: #e53e3e;
    box-shadow: 0 0 0 3px rgba(229, 62, 62, 0.1);
}

/* 에러 메시지 */
.error-message {
    display: none;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background: #fff5f5;
    border: 1px solid #fed7d7;
    border-radius: 10px;
    margin-bottom: 20px;
    animation: shake 0.4s ease-out;
}

.error-message.show {
    display: flex;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-6px); }
    75% { transform: translateX(6px); }
}

.error-message .error-icon {
    width: 18px;
    height: 18px;
    background: #e53e3e;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 11px;
    font-weight: 700;
    flex-shrink: 0;
}

.error-message .error-text {
    font-size: 13px;
    color: #c53030;
    line-height: 1.4;
}

/* 로그인 버튼 */
.login-btn {
    width: 100%;
    padding: 15px;
    background: #00A3E0; /* Cyan Blue */
    color: #fff;
    border: none;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.login-btn:hover {
    background: #008cc2; /* Cyan Blue Darker */
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(0, 163, 224, 0.3);
}

.login-btn:active {
    transform: translateY(0);
}

.login-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* 로딩 스피너 */
.login-btn .spinner {
    display: none;
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    margin: 0 auto;
}

.login-btn.loading .btn-text {
    display: none;
}

.login-btn.loading .spinner {
    display: inline-block;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 푸터 */
.login-footer {
    text-align: center;
    margin-top: 28px;
    font-size: 12px;
    color: rgba(255, 255, 255, 0.5);
    letter-spacing: 0.5px;
}

/* 반응형 */
@media (max-width: 480px) {
    .login-wrapper {
        padding: 16px;
    }
    
    .login-card {
        padding: 36px 28px;
        border-radius: 12px;
    }
    
    .login-logo h1 {
        font-size: 24px;
    }

    .form-group input {
        padding: 12px 14px;
        font-size: 16px; /* 모바일에서 줌 방지 */
    }

    .login-btn {
        padding: 14px;
    }
}

@media (max-width: 360px) {
    .login-card {
        padding: 28px 20px;
    }

    .login-logo h1 {
        font-size: 22px;
    }
}