:root {
    --primary-blue: #0071e3;
    --bg-gradient: radial-gradient(circle at top left, #ffffff 0%, #f5f5f7 40%, #e2e2e7 100%);
    --card-bg: rgba(255, 255, 255, 0.72);
    --text-main: #1d1d1f;
    --text-sub: #86868b;
    --input-bg: rgba(255, 255, 255, 0.8);
    --input-border: rgba(0, 0, 0, 0.12);
    --glass-blur: blur(25px);
}

.night-mode {
    --bg-gradient: radial-gradient(circle at top left, #1c1c1e 0%, #0a0a0c 100%);
    --card-bg: rgba(28, 28, 30, 0.75);
    --text-main: #f5f5f7;
    --text-sub: #86868b;
    --input-bg: rgba(255, 255, 255, 0.05);
    --input-border: rgba(255, 255, 255, 0.15);
}

* { box-sizing: border-box; }
body { 
    margin: 0; 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; 
    background: var(--bg-gradient);
    height: 100vh; 
    display: flex; 
    align-items: center; 
    justify-content: center;
    overflow: hidden;
    color: var(--text-main);
    transition: background 1.5s ease-in-out; 
}

body::before {
    content: ""; position: fixed; inset: 0;
    background: radial-gradient(circle at 30% 30%, rgba(0, 113, 227, 0.08) 0%, transparent 50%),
                radial-gradient(circle at 70% 70%, rgba(0, 113, 227, 0.05) 0%, transparent 50%);
    animation: breathAmbient 45s ease-in-out infinite alternate;
    pointer-events: none; z-index: -1;
}

@keyframes breathAmbient {
    from { transform: translate(0, 0) scale(1); opacity: 0.5; }
    to { transform: translate(50px, 30px) scale(1.1); opacity: 0.8; }
}

.login-card {
    width: 380px;
    padding: 45px 40px;
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 40px 100px rgba(0,0,0,0.12);
    text-align: center;
    animation: slideUp 0.8s cubic-bezier(0,0,0,1);
}

@keyframes slideUp { from { transform: translateY(40px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }

.logo-container { margin-bottom: 30px; }
.logo-img { width: 95px; height: 95px; border-radius: 50%; border: 3px solid var(--primary-blue); box-shadow: 0 0 25px rgba(0,113,227,0.25); }
.brand-title { font-size: 28px; font-weight: 800; margin-top: 18px; letter-spacing: -1.2px; }
.subtitle { font-size: 13px; color: var(--text-sub); margin-bottom: 35px; letter-spacing: 0.8px; text-transform: uppercase; font-weight: 600; }

.form-group { margin-bottom: 24px; text-align: left; }
.form-group label { display: block; font-size: 10px; font-weight: 700; color: var(--primary-blue); margin-left: 14px; margin-bottom: 8px; text-transform: uppercase; letter-spacing: 1.2px; }
.form-group input { 
    width: 100%; padding: 16px 22px; border-radius: 16px; 
    border: 1.5px solid var(--input-border); background: var(--input-bg); 
    font-size: 16px; outline: none; transition: all 0.3s; color: var(--text-main);
}
.form-group input:focus { 
    border-color: var(--primary-blue); 
    box-shadow: 0 0 0 5px rgba(0,113,227,0.15); 
}

.btn-login { 
    width: 100%; padding: 18px; border-radius: 16px; border: none; 
    background: var(--primary-blue); color: white; font-size: 17px; font-weight: 700;
    cursor: pointer; transition: all 0.3s; margin-top: 15px;
    box-shadow: 0 8px 25px rgba(0,113,227,0.3);
}

.btn-login:hover { transform: translateY(-2px); box-shadow: 0 12px 35px rgba(0,113,227,0.45); filter: brightness(1.05); }
.btn-login:active { transform: scale(0.97); }
.btn-login:disabled { background: #aeaeae; cursor: not-allowed; box-shadow: none; }

.error-msg { 
    color: #ff3b30; font-size: 13px; font-weight: 600; 
    margin-top: 20px; display: none; background: rgba(255,59,48,0.08); 
    padding: 12px; border-radius: 12px; border: 1px solid rgba(255,59,48,0.2);
}

#version-tag { position: fixed; bottom: 25px; width: 100%; text-align: center; font-size: 11px; color: var(--text-sub); letter-spacing: 1px; }