@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;800&family=Noto+Sans+JP:wght@300;400;700&display=swap');

:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.3);
    --text-main: #1e293b;
    --text-muted: #64748b;
}

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

html, body {
    height: 100%;
    margin: 0;
}

body {
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    background-image: url('login_bg.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow-y: auto;
}

body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at center, transparent 0%, rgba(0,0,0,0.2) 100%);
    z-index: 0;
}

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

.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid var(--glass-border);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    border-radius: 24px;
}

.form-container {
    padding: 40px;
    text-align: center;
    transition: all 0.5s ease;
}

.header {
    margin-bottom: 30px;
}

.logo {
    font-size: 3rem;
    margin-bottom: 10px;
    filter: drop-shadow(0 10px 15px rgba(0,0,0,0.1));
}

.header h1 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.025em;
    margin-bottom: 5px;
}

.header p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.input-group {
    margin-bottom: 15px;
}

.input-group input {
    width: 100%;
    padding: 15px 20px;
    border-radius: 12px;
    border: 1px solid rgba(0, 0, 0, 0.05);
    background: rgba(255, 255, 255, 0.5);
    font-size: 0.95rem;
    color: var(--text-main);
    outline: none;
    transition: all 0.3s ease;
}

.input-group input:focus {
    background: #fff;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
}

.submit-btn {
    width: 100%;
    padding: 15px;
    border-radius: 12px;
    border: none;
    background: var(--primary-color);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 10px 15px -3px rgba(79, 70, 229, 0.3);
    margin-top: 10px;
}

.submit-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 20px 25px -5px rgba(79, 70, 229, 0.4);
}

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

.message {
    margin-top: 25px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.message a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

.message a:hover {
    color: var(--primary-hover);
}

.hidden {
    display: none;
}

/* アニメーション用クラス */
.fade-in {
    animation: fadeIn 0.5s forwards;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 480px) {
    .form-container {
        padding: 30px 20px;
    }
}