:root {
    --primary-color: #00f0ff;
    --secondary-color: #0066ff;
    --background-color: #000;
    --grid-color: rgba(0, 240, 255, 0.1);
    --text-color: #fff;
    --input-bg: rgba(0, 0, 0, 0.7);
    --input-border: 1px solid rgba(0, 240, 255, 0.5);
    --timer-size: min(80vw, 80vh, 600px);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Rajdhani', sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    position: relative;
    font-family: 'Rajdhani', sans-serif;
}

.cyber-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, rgba(0, 30, 60, 0.8) 0%, rgba(0, 0, 0, 1) 70%);
    z-index: -2;
}

.grid {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(var(--grid-color) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
    background-size: 30px 30px;
    z-index: -1;
    animation: grid-movement 20s linear infinite;
    will-change: background-position, transform;
    transform: translateZ(0); /* GPU 가속 */
}

@keyframes grid-movement {
    0% {
        background-position: 0 0;
    }
    100% {
        background-position: 30px 30px;
    }
}

.timer-circle {
    width: var(--timer-size);
    height: var(--timer-size);
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 0 30px rgba(0, 240, 255, 0.3);
    aspect-ratio: 1/1;
}

.timer-progress {
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 2px solid transparent;
    border-top: 2px solid var(--primary-color);
    border-right: 2px solid var(--primary-color);
    animation: spin 30s linear infinite;
    will-change: transform;
    transform: translateZ(0); /* GPU 가속 */
}

.timer-spinner {
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 1px solid transparent;
    border-bottom: 1px dashed rgba(0, 240, 255, 0.3);
    animation: spin 15s linear infinite;
    will-change: transform;
    transform: translateZ(0); /* GPU 가속 */
}

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

.timer-text {
    position: absolute;
    font-size: 40px;
    color: var(--primary-color);
    font-weight: bold;
    text-shadow: 0 0 5px var(--primary-color);
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    z-index: 1;
}

.login-container {
    background-color: rgba(0, 0, 20, 0.7);
    border: 1px solid var(--primary-color);
    padding: 30px;
    border-radius: 5px;
    width: 85%;
    max-width: 400px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    backdrop-filter: blur(10px);
    box-shadow: 0 0 15px rgba(0, 240, 255, 0.2);
    z-index: 1;
}

.login-title {
    color: var(--primary-color);
    margin-bottom: 15px;
    text-align: center;
    font-size: 24px;
    letter-spacing: 1px;
    text-transform: uppercase;
    text-shadow: 0 0 5px var(--primary-color);
}

.input-group {
    margin-bottom: 12px;
}

.input-group label {
    display: block;
    margin-bottom: 5px;
    color: var(--primary-color);
    font-size: 14px;
}

.input-group input {
    width: 100%;
    padding: 6px 8px;
    background-color: var(--input-bg);
    border: var(--input-border);
    color: var(--text-color);
    border-radius: 3px;
    outline: none;
    transition: all 0.3s;
    font-size: 14px;
    line-height: 1.4;
}

.input-group input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 5px var(--primary-color);
}

.remember-me {
    display: flex;
    align-items: center;
    margin-bottom: 12px;
}

.remember-me input {
    margin-right: 10px;
    accent-color: var(--primary-color);
}

.login-btn {
    width: 100%;
    padding: 10px;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    color: #000;
    border: none;
    border-radius: 3px;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.3s;
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.login-btn:hover {
    background: linear-gradient(to right, var(--secondary-color), var(--primary-color));
    box-shadow: 0 0 10px var(--primary-color);
}

.links {
    display: flex;
    justify-content: space-between;
    font-size: 14px;
}

.links a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s;
}

.links a:hover {
    text-shadow: 0 0 5px var(--primary-color);
}

.alert {
    padding: 10px;
    margin-bottom: 15px;
    border-radius: 3px;
    font-size: 14px;
}

.alert-warning {
    background-color: rgba(255, 200, 0, 0.2);
    border: 1px solid rgba(255, 200, 0, 0.5);
    color: #ffc800;
}

.alert-danger {
    background-color: rgba(255, 0, 0, 0.2);
    border: 1px solid rgba(255, 0, 0, 0.5);
    color: #ff5555;
}

/* 로그인 정보 스타일 */
.login-info {
    margin: 8px 0;
    font-size: 0.8em;
    color: #aaa;
    text-align: center;
}

/* 소셜 로그인 컨테이너 */
.social-login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
    padding: 6px 0;
    min-height: 32px;
    width: 100%;
    flex-wrap: nowrap;
    /* 소셜 로그인이 없을 때도 공간 유지 (컨테이너 크기 일관성) */
}

/* 소셜 로그인 아이콘 스타일 */
.social-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: 1 1 auto;
    min-width: 0;
    max-width: 50px;
    height: 32px;
    border-radius: 4px;
    background-color: rgba(0, 240, 255, 0.1);
    border: 1px solid rgba(0, 240, 255, 0.3);
    transition: all 0.3s ease;
    cursor: pointer;
    text-decoration: none;
    overflow: hidden;
    position: relative;
}

.social-icon:hover {
    background-color: rgba(0, 240, 255, 0.2);
    border-color: var(--primary-color);
    box-shadow: 0 0 8px rgba(0, 240, 255, 0.4);
    transform: translateY(-2px);
}

.social-icon:active {
    transform: translateY(0);
}

.social-icon img {
    width: 18px;
    height: 18px;
    object-fit: contain;
    filter: brightness(0.9);
    transition: all 0.3s ease;
}

.social-icon:hover img {
    filter: brightness(1.1);
    transform: scale(1.1);
}

@media (max-width: 480px) {
    :root {
        --timer-size: min(90vw, 90vh, 300px);
    }
    
    .login-container {
        padding: 20px;
        width: 90%;
        max-width: 320px;
    }
    
    .social-login-container {
        gap: 6px;
        min-height: 28px;
        padding: 4px 0;
    }
    
    .social-icon {
        max-width: 45px;
        height: 28px;
    }
    
    .social-icon img {
        width: 16px;
        height: 16px;
    }
}