/* 基本設定 */
:root {
    --primary-color: #3a7bd5;
    --primary-gradient: linear-gradient(135deg, #3a7bd5 0%, #00d2ff 100%);
    --secondary-color: #00d2ff;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --accent-color: #ff9e2c;
    --success-color: #2ecc71;
    --danger-color: #e74c3c;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    background: var(--dark-color);
    background-image: url('https://images.unsplash.com/photo-1517960413843-0aee8e2b3285?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=85'); /* 教育と旅行をイメージした背景 */
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    position: relative;
}

body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.6); /* 暗いオーバーレイ */
    z-index: -1;
}

h1, h2, h3, h4, h5, h6, .btn {
    font-family: 'Poppins', 'Noto Sans JP', sans-serif;
}

/* ログインコンテナ */
.login-container {
    min-height: 100vh;
    position: relative;
    z-index: 1;
}

.login-wrapper {
    background: white;
    border-radius: 16px !important;
    overflow: hidden;
    transition: all 0.3s ease;
}

/* 左側イメージエリア */
.login-image-container {
    background-image: url('https://images.unsplash.com/photo-1501555088652-021faa106b9b?ixlib=rb-1.2.1&auto=format&fit=crop&w=1398&q=80'); /* 教室と海岸を組み合わせた画像に変更するとよい */
    background-size: cover;
    background-position: center;
    position: relative;
}

.login-image-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    opacity: 0.9; /* 少し透過 */
    padding: 3rem;
}

.logo-text {
    font-weight: 700;
    font-size: 2.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: relative;
}

.logo-text::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 40px;
    height: 4px;
    background: var(--accent-color);
    border-radius: 2px;
}

.tagline {
    font-size: 1.3rem;
    font-weight: 300;
    line-height: 1.6;
    opacity: 0.9;
}

.feature-item {
    font-size: 1rem;
    display: flex;
    align-items: center;
    opacity: 0.9;
    transition: all 0.3s ease;
}

.feature-item:hover {
    transform: translateX(5px);
    opacity: 1;
}

.feature-item i {
    color: var(--accent-color);
    font-size: 1.2rem;
}

/* ログインフォーム */
.login-form-container {
    padding: 3rem;
}

.brand-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary-gradient);
    color: white;
    font-size: 1.2rem;
}

.form-title {
    color: var(--dark-color);
    font-weight: 600;
    font-size: 1.8rem;
    margin: 0;
}

.form-control {
    height: 56px;
    border-radius: 8px;
    border: 1px solid #e0e0e0;
    padding-left: 1rem;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(58, 123, 213, 0.1);
}

.form-floating label {
    padding-left: 1rem;
    color: #aaa;
}

.btn {
    border-radius: 8px;
    font-weight: 500;
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--primary-gradient);
    border: none;
    box-shadow: 0 4px 10px rgba(58, 123, 213, 0.3);
}

.btn-primary:hover, .btn-primary:focus {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(58, 123, 213, 0.4);
}

.btn-outline-secondary {
    border: 1px solid #e0e0e0;
    color: var(--dark-color);
}

.btn-outline-secondary:hover {
    background-color: #f8f9fa;
    color: var(--primary-color);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.form-check-input:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.2s ease;
}

a:hover {
    color: var(--secondary-color);
}

.copyright {
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

/* アニメーション */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translate3d(0, 30px, 0);
    }
    to {
        opacity: 1;
        transform: translate3d(0, 0, 0);
    }
}

.fadeInUp {
    animation: fadeInUp 0.6s ease forwards;
}

/* レスポンシブ調整 */
@media (max-width: 767.98px) {
    .login-wrapper {
        margin: 1rem;
    }
    
    .login-form-container {
        padding: 2rem;
    }
    
    .form-title {
        font-size: 1.5rem;
    }
}

@media (min-width: 992px) {
    .login-wrapper {
        max-width: 1000px;
        margin: 0 auto;
    }
}

/* アクセシビリティ向上のためのフォーカス表示 */
a:focus, button:focus, input:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}