:root {
    --bg-color: #f9fafb;
    --text-color: #111827;
    --primary-color: #0066cc;
    --primary-hover: #004c99;
    --secondary-color: #4b5563;
    --accent-color: #059669;
    --border-color: #9ca3af;
    --card-bg: #ffffff;
    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --font-sans: 'Inter', 'Noto Sans JP', sans-serif;
    --input-bg: #ffffff;
    --header-bg: #ffffff;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    font-size: 16px;
    /* Ensure base font size is large enough */
}

/* Hide the gradient background from the previous theme */
.background-gradient {
    display: none;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    color: #000000;
    font-weight: 700;
    margin-bottom: 1rem;
}

h1 {
    font-size: 2rem;
}

h2 {
    font-size: 1.75rem;
    border-bottom: 2px solid #e5e7eb;
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.5rem;
}

a {
    color: var(--primary-color);
    text-decoration: underline;
    /* Underline for better link visibility */
    transition: color 0.2s;
}

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

/* Layout */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navbar */
.navbar {
    background: var(--header-bg);
    border-bottom: 2px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.navbar-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: #000000;
    text-decoration: none;
}

.nav-menu {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-link {
    color: #374151;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
}

.nav-link:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

.btn-text {
    background: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
    padding: 0;
}

.inline-form {
    display: inline-block;
}

/* Messages */
.messages {
    margin-bottom: 2rem;
}

.alert {
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    border: 2px solid transparent;
    font-weight: 500;
}

.alert-error,
.alert-danger {
    background-color: #fee2e2;
    border-color: #ef4444;
    color: #991b1b;
}

.alert-success {
    background-color: #d1fae5;
    border-color: #10b981;
    color: #065f46;
}

.alert-warning {
    background-color: #fef3c7;
    border-color: #f59e0b;
    color: #92400e;
}

.alert-info {
    background-color: #dbeafe;
    border-color: #3b82f6;
    color: #1e40af;
}

/* Main Content */
.main-content {
    flex: 1;
    padding-top: 2rem;
    padding-bottom: 2rem;
}

/* Footer */
.footer {
    background: #f3f4f6;
    border-top: 2px solid var(--border-color);
    padding: 2rem 0;
    text-align: center;
    color: #4b5563;
    margin-top: auto;
}

/* Cards */
.card {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 1.5rem;
    box-shadow: none;
    /* Removed shadow for simpler look, or keep minimal */
    margin-bottom: 1.5rem;
}

.card-header {
    margin-bottom: 1rem;
    border-bottom: 2px solid #e5e7eb;
    padding-bottom: 0.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 700;
    color: #111827;
    font-size: 1.05rem;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
input[type="date"],
input[type="datetime-local"],
select,
textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--input-bg);
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    color: #000000;
    font-family: inherit;
    font-size: 1rem;
    transition: all 0.2s;
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.2);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
    border: 2px solid transparent;
    text-decoration: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    text-decoration: none;
}

.btn-secondary {
    background-color: #9ca3af;
    color: white;
}

.btn-secondary:hover {
    background-color: #6b7280;
    text-decoration: none;
}

.btn-danger {
    background-color: #dc2626;
    color: white;
}

.btn-danger:hover {
    background-color: #b91c1c;
    text-decoration: none;
}

/* FullCalendar Customization (High Contrast) */
:root {
    --fc-border-color: #6b7280;
    --fc-page-bg-color: #ffffff;
    --fc-neutral-bg-color: #f3f4f6;
    --fc-list-event-hover-bg-color: #e5e7eb;
    --fc-today-bg-color: #fffbeb;
    /* Light yellow for today */
}

.fc {
    color: #000000;
}

.fc a {
    text-decoration: none;
    color: #000000;
}

.fc .fc-toolbar-title {
    color: #000000;
}

.fc .fc-button-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
    font-weight: bold;
}

.fc .fc-button-primary:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
}

.fc .fc-col-header-cell-cushion {
    color: #111827;
    font-weight: bold;
}

.fc .fc-daygrid-day-number {
    color: #111827;
    font-weight: 500;
    font-size: 1.1em;
    padding: 4px 8px;
}

/* Selected date highlight in Calendar */
.fc-day-selected {
    background-color: #fef08a !important;
    /* Yellow-200 equivalent */
    position: relative;
    border: 2px solid var(--primary-color) !important;
}

.fc-day-selected::after {
    content: "もう一度クリックで予約";
    position: absolute;
    bottom: 2px;
    left: 0;
    right: 0;
    text-align: center;
    font-size: 0.75rem;
    color: var(--primary-color);
    font-weight: bold;
    pointer-events: none;
}