:root {
    --primary: #4FC3F7;
    --primary-dark: #29B6F6;
    --success: #4CAF50;
    --error: #f44336;
    --warning: #ff9800;
    --text: #333;
    --text-light: #666;
    --border: #e0e0e0;
    --background: #f5f5f5;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', sans-serif;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 24px;
    padding: 48px 40px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.15);
    max-width: 440px;
    width: 100%;
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 32px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
}

h1 {
    color: var(--text);
    font-size: 28px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 8px;
}

.subtitle {
    color: var(--text-light);
    text-align: center;
    margin-bottom: 32px;
    font-size: 14px;
}

/* フォーム */
.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    color: var(--text);
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 12px;
    font-size: 16px;
    transition: all 0.3s;
    outline: none;
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 195, 247, 0.1);
}

.form-control.error {
    border-color: var(--error);
}

/* ボタン */
.btn {
    width: 100%;
    padding: 14px;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(79, 195, 247, 0.3);
}

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

/* ローディング */
.loading {
    text-align: center;
    padding: 40px;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 24px;
}

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

/* メッセージ */
.message {
    text-align: center;
    padding: 40px;
}

.message-card {
    padding: 24px;
    border-radius: 16px;
    margin-bottom: 32px;
    animation: fadeIn 0.5s;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.success-message {
    background: #e8f5e9;
    color: #2e7d32;
}

.error-message {
    background: #ffebee;
    color: #c62828;
}

.warning-message {
    background: #fff3e0;
    color: #ef6c00;
}

/* アイコン */
.icon-large {
    font-size: 64px;
    margin-bottom: 24px;
    display: block;
    text-align: center;
}

/* エラーメッセージ */
.error-text {
    color: var(--error);
    font-size: 12px;
    margin-top: 4px;
    display: none;
}

.error-text.show {
    display: block;
}

/* リンク */
.link {
    color: var(--primary);
    text-decoration: none;
    font-size: 14px;
}

.link:hover {
    text-decoration: underline;
}

.footer-link {
    text-align: center;
    margin-top: 24px;
}

/* レスポンシブ */
@media (max-width: 480px) {
    .container {
        padding: 32px 24px;
    }

    h1 {
        font-size: 24px;
    }

    .form-control {
        font-size: 16px;
    }
}