:root {
    --Primary-Primary700: #2E66F6;
    --Primary-Primary500: #769DFF;
    --semantic-color-text-text-default: #1C1D23;
    --semantic-color-text-text-sub: #737783;
    --semantic-color-text-text-main: #50545F;
    --GrayScale-Gray200: #F3F5F9;
    --GrayScale-Gray100: #FFF;
    --GrayScale-Gray300: #E5E8F0;
    --GrayScale-Gray400: #C4CAD4;
    --GrayScale-Gray600: #9AA0AC;
    --GrayScale-Gray800: #434753;
    --semantic-color-background-component-bg: #FFF;
    --semantic-color-background-divider-1: #BDC2CE;
    --bs-danger: #DC3545;
    --bs-success: #198754;
}

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

html, body {
    height: 100%;
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    overflow: hidden;
}

.login-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    position: relative;
}

.login-card {
    background: var(--semantic-color-background-component-bg);
    border-radius: 1.5rem;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    padding: 3rem;
    width: 100%;
    max-width: 480px;
    position: relative;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* 로고 섹션 */
.logo-section {
    text-align: center;
}

.logo {
    width: 240px;
    height: 120px;
    margin-bottom: 1rem;
    object-fit: contain;
}

.app-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--semantic-color-text-text-default);
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
}

.app-subtitle {
    font-size: 1rem;
    color: var(--semantic-color-text-text-sub);
    font-weight: 400;
    margin-bottom: 0;
    letter-spacing: -0.01em;
}

/* 폼 섹션 */
.form-section {
    width: 100%;
}

.login-form {
    width: 100%;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--semantic-color-text-text-main);
    margin-bottom: 0.5rem;
    letter-spacing: -0.01em;
}

.form-control {
    width: 100%;
    height: 3rem;
    padding: 0 1rem;
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: var(--semantic-color-text-text-default);
    background-color: var(--GrayScale-Gray100);
    border: 1.5px solid var(--GrayScale-Gray300);
    border-radius: 0.75rem;
    transition: all 0.2s ease-in-out;
    letter-spacing: -0.01em;
}

.form-control:focus {
    outline: none;
    border-color: var(--Primary-Primary500);
    box-shadow: 0 0 0 3px rgba(118, 157, 255, 0.1);
    background-color: var(--GrayScale-Gray100);
}

.form-control::placeholder {
    color: var(--semantic-color-text-text-sub);
    font-weight: 400;
}

.form-control:hover:not(:focus) {
    border-color: var(--GrayScale-Gray400);
}

/* 체크박스 그룹 */
.form-check-group {
    margin-bottom: 1rem;
}

.form-check {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-check-input {
    width: 1.125rem;
    height: 1.125rem;
    margin: 0;
    border: 1.5px solid var(--GrayScale-Gray300);
    border-radius: 0.25rem;
    background-color: var(--GrayScale-Gray100);
    cursor: pointer;
    transition: all 0.2s ease-in-out;
    flex-shrink: 0;
}

.form-check-input:checked {
    background-color: var(--Primary-Primary500);
    border-color: var(--Primary-Primary500);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3e%3cpath fill='none' stroke='%23fff' stroke-linecap='round' stroke-linejoin='round' stroke-width='3' d='m6 10 3 3 6-6'/%3e%3c/svg%3e");
}

.form-check-input:focus {
    outline: none;
    border-color: var(--Primary-Primary500);
    box-shadow: 0 0 0 3px rgba(118, 157, 255, 0.1);
}

.form-check-input:hover:not(:checked) {
    border-color: var(--GrayScale-Gray400);
}

.form-check-label {
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--semantic-color-text-text-main);
    cursor: pointer;
    letter-spacing: -0.01em;
    user-select: none;
}

/* 로그인 버튼 */
.btn-login {
    width: 100%;
    height: 3.5rem;
    background: linear-gradient(135deg, var(--Primary-Primary700) 0%, var(--Primary-Primary500) 100%);
    border: none;
    border-radius: 0.75rem;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    transition: all 0.2s ease-in-out;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 1rem;
    position: relative;
    overflow: hidden;
}

.btn-login:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: 0 8px 25px rgba(46, 102, 246, 0.3);
    background: linear-gradient(135deg, #1e4ed8 0%, #6366f1 100%);
    color: white;
}

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

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

.btn-login .btn-text {
    transition: opacity 0.2s ease-in-out;
}

.btn-login.loading .btn-text {
    opacity: 0;
}

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

/* 에러 메시지 */
.error-message {
    background-color: rgba(220, 53, 69, 0.1);
    border: 1px solid rgba(220, 53, 69, 0.2);
    color: var(--bs-danger);
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    margin-top: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    animation: shake 0.5s ease-in-out;
}

.error-message i {
    font-size: 1rem;
    flex-shrink: 0;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

/* 푸터 */
.login-footer {
    position: absolute;
    bottom: 1rem;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    width: 100%;
}

.login-footer p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
    font-weight: 400;
    margin: 0;
}

/* 반응형 디자인 */
@media (max-width: 576px) {
    .login-container {
        padding: 1rem;
    }
    
    .login-card {
        padding: 2rem 1.5rem;
        border-radius: 1rem;
    }
    
    .app-title {
        font-size: 1.75rem;
    }
    
    .app-subtitle {
        font-size: 0.9rem;
    }
    
    .form-control {
        height: 2.75rem;
        font-size: 0.9rem;
    }
    
    .btn-login {
        height: 3rem;
        font-size: 0.9rem;
    }
    
    .logo {
        width: 200px;
        height: 100px;
    }
}

@media (max-width: 375px) {
    .login-card {
        padding: 1.5rem 1rem;
    }
    
    .logo-section {
        margin-bottom: 2rem;
    }
    
    .form-group {
        margin-bottom: 1.25rem;
    }
}

/* 접근성 개선 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 다크 모드 지원 */
@media (prefers-color-scheme: dark) {
    body {
        background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    }
}

/* 포커스 표시 개선 */
.form-control:focus,
.btn-login:focus {
    outline: 2px solid var(--Primary-Primary500);
    outline-offset: 2px;
}

/* 로딩 상태 애니메이션 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-card {
    animation: fadeInUp 0.6s ease-out;
}

/* 성공 메시지 (향후 사용) */
.success-message {
    background-color: rgba(25, 135, 84, 0.1);
    border: 1px solid rgba(25, 135, 84, 0.2);
    color: var(--bs-success);
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    margin-top: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}