/* ===========================================
   Body & Global
=========================================== */
body {
    background: linear-gradient(135deg, #6a11cb, #2575fc);
    font-family: 'Segoe UI', sans-serif;
    color: #fff;
    margin: 0;
    padding: 0;
    min-height: 100vh;
}

/* ===========================================
   Card
=========================================== */
.card {
    background-color: rgba(0,0,0,0.7);
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.5);
    padding: 30px;
    margin: auto;
    max-width: 500px;
    color: #fff;
}

/* ===========================================
   Headings
=========================================== */
h1, h2, h3, h4, h5, h6 {
    color: #fff;
    text-align: center;
}

/* ===========================================
   Form Controls
=========================================== */
input.form-control,
textarea.form-control {
    width: 100%;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255,255,255,0.3);
    color: #fff;
    padding: 10px 15px;
    font-size: 16px;
    box-sizing: border-box;
    margin-bottom: 15px;
}

input.form-control::placeholder,
textarea.form-control::placeholder {
    color: rgba(255,255,255,0.7);
}

/* 高さ調整 */
textarea.form-control {
    height: 120px;
    resize: none;
}

/* ===========================================
   Labels & Text
=========================================== */
.card label,
.card .form-label {
    color: #fff;
}

.card label.fw-bold {
    font-weight: 600;
    font-size: 1rem;
}

/* ===========================================
   Buttons
=========================================== */
.btn-primary {
    width: 100%;
    border-radius: 12px;
    font-weight: bold;
    padding: 12px;
    font-size: 1rem;
}

.btn-custom {
    display: block;
    margin: 10px auto;
    padding: 12px 0;
    width: 80%;
    max-width: 300px;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: bold;
    text-decoration: none;
    transition: background 0.3s ease;
}

.btn-login {
    background-color: #28a745;
    color: #fff;
}

.btn-login:hover {
    background-color: #218838;
    color: #fff;
}

.btn-register {
    background-color: #007bff;
    color: #fff;
}

.btn-register:hover {
    background-color: #0069d9;
    color: #fff;
}

/* ===========================================
   Tabs
=========================================== */
.nav-tabs .nav-link {
    border-radius: 10px 10px 0 0;
    margin-bottom: 5px;
    color: #fff;
}

.nav-tabs .nav-link.active {
    background-color: rgba(40,167,69,0.8);
    color: #fff;
}

/* ===========================================
   Responsive
=========================================== */
@media (max-width: 576px) {
    .card {
        padding: 15px;
        margin: 10px;
    }

    .nav-tabs .nav-link {
        font-size: 0.9rem;
        padding: 8px;
    }
}
/* ホームカード */
.btn-primary {
    background-color: #28a745;
    border: none;
    color: #fff;
}

.btn-success {
    background-color: #007bff;
    border: none;
    color: #fff;
}

.btn-secondary {
    background-color: #6c757d;
    border: none;
    color: #fff;
}

.btn-third {
    background-color: #ff6600;
    border: none;
    color: #fff;
}

.btn-primary:hover,
.btn-success:hover,
.btn-secondary:hover,
.btn-third:hover {
    opacity: 0.9;
}