/* ===== リセットと基本設定 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --error-color: #dc2626;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

/* ===== 背景アニメーション ===== */
.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}

.circle {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    animation: float 20s infinite ease-in-out;
}

.circle-1 {
    width: 300px;
    height: 300px;
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.circle-2 {
    width: 200px;
    height: 200px;
    top: 60%;
    right: 10%;
    animation-delay: 5s;
}

.circle-3 {
    width: 150px;
    height: 150px;
    bottom: 10%;
    left: 50%;
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) rotate(0deg);
        opacity: 0.3;
    }
    50% {
        transform: translateY(-50px) rotate(180deg);
        opacity: 0.6;
    }
}

/* ===== ログインコンテナ ===== */
.login-container {
    position: relative;
    z-index: 10;
    width: 100%;
    max-width: 450px;
    padding: 20px;
}

.login-box {
    background-color: var(--bg-primary);
    border-radius: 20px;
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    animation: slideIn 0.5s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== ログインヘッダー ===== */
.login-header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 40px 30px;
    text-align: center;
}

.login-header .logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    backdrop-filter: blur(10px);
}

.login-header h1 {
    font-size: 1.6rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.login-header p {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* ===== ログインボディ ===== */
.login-body {
    padding: 40px 30px;
}

.login-body h2 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
    text-align: center;
}

.login-description {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 35px;
    font-size: 0.95rem;
}

/* ===== PINコード入力 ===== */
.pin-input-container {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 25px;
}

.pin-input {
    width: 60px;
    height: 70px;
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    transition: var(--transition);
    font-family: 'Noto Sans JP', sans-serif;
}

.pin-input:focus {
    outline: none;
    border-color: var(--primary-color);
    background-color: white;
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
    transform: scale(1.05);
}

.pin-input.error {
    border-color: var(--error-color);
    animation: shake 0.5s ease;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

/* ===== エラーメッセージ ===== */
.error-message {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px;
    background-color: #fee2e2;
    color: var(--error-color);
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    animation: slideDown 0.3s ease;
}

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

/* ===== ログインボタン ===== */
.login-btn {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-family: 'Noto Sans JP', sans-serif;
}

.login-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.login-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* ===== ログインフッター ===== */
.login-footer {
    background-color: var(--bg-secondary);
    padding: 20px;
    text-align: center;
}

.login-footer p {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* ===== フォームグループ ===== */
.form-group-login {
    margin-bottom: 20px;
    text-align: left;
}

.form-group-login label {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    font-size: 0.95rem;
}

.form-group-login label i {
    margin-right: 8px;
    color: var(--primary-color);
}

.form-input-login {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: 'Noto Sans JP', sans-serif;
    transition: var(--transition);
}

.form-input-login:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* ===== 戻るリンク ===== */
.back-link {
    text-align: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.back-link a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.back-link a:hover {
    color: var(--primary-dark);
}

.back-link i {
    margin-right: 6px;
}

/* ===== レスポンシブデザイン ===== */
@media (max-width: 768px) {
    .login-container {
        padding: 15px;
    }

    .login-header {
        padding: 35px 25px;
    }

    .login-header .logo {
        width: 75px;
        height: 75px;
        font-size: 2.2rem;
    }

    .login-header h1 {
        font-size: 1.5rem;
    }

    .login-header p {
        font-size: 0.9rem;
    }

    .login-body {
        padding: 35px 25px;
    }

    .login-body h2 {
        font-size: 1.6rem;
    }

    .login-description {
        font-size: 0.9rem;
        margin-bottom: 30px;
    }

    .pin-input-container {
        gap: 12px;
    }

    .pin-input {
        width: 55px;
        height: 65px;
        font-size: 1.8rem;
    }

    .login-btn {
        padding: 15px;
        font-size: 1.05rem;
    }

    .login-footer {
        padding: 18px;
    }

    .login-footer p {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .login-container {
        padding: 10px;
    }

    .login-header {
        padding: 30px 20px;
    }

    .login-header .logo {
        width: 65px;
        height: 65px;
        font-size: 1.8rem;
        margin-bottom: 15px;
    }

    .login-header h1 {
        font-size: 1.3rem;
        margin-bottom: 6px;
    }

    .login-header p {
        font-size: 0.85rem;
    }

    .login-body {
        padding: 30px 20px;
    }

    .login-body h2 {
        font-size: 1.4rem;
        margin-bottom: 8px;
    }

    .login-description {
        font-size: 0.85rem;
        margin-bottom: 28px;
    }

    .pin-input-container {
        gap: 10px;
        margin-bottom: 22px;
    }

    .pin-input {
        width: 50px;
        height: 60px;
        font-size: 1.6rem;
        border-radius: 10px;
    }

    .login-btn {
        padding: 14px;
        font-size: 1rem;
        border-radius: 10px;
    }

    .error-message {
        padding: 11px;
        font-size: 0.85rem;
        margin-bottom: 18px;
    }

    .success-message i {
        font-size: 1.1rem;
    }

    .login-footer {
        padding: 16px;
    }

    .login-footer p {
        font-size: 0.75rem;
    }

    .circle-1, .circle-2, .circle-3 {
        display: none;
    }
}