@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@300;400;700&display=swap');

:root {
    --bg-color: #121212;
    --primary-text-color: #e0e0e0;
    --secondary-text-color: #b3b3b3;
    --border-color: #282828;
    --header-bg-color: #1d1d1d;
    --sunday-color: #ff6b6b;
    --saturday-color: #6b95ff;
    --holiday-color: #ff6b6b;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --hover-bg-color: rgba(255, 255, 255, 0.12);
}

[data-theme="light"] {
    --bg-color: #f5f6f8;
    --primary-text-color: #212529;
    --secondary-text-color: #6c757d;
    --border-color: #dee2e6;
    --header-bg-color: #ffffff;
    --sunday-color: #dc3545;
    --saturday-color: #0d6efd;
    --holiday-color: #dc3545;
    --shadow-color: rgba(0, 0, 0, 0.05);
    --hover-bg-color: rgba(0, 0, 0, 0.07);
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    background-color: var(--bg-color);
    color: var(--primary-text-color);
    margin: 0;
    padding: 1rem;
}

header {
    background-color: var(--header-bg-color);
    padding: 1rem 2rem;
    margin-bottom: 1rem;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    border: 1px solid var(--border-color);
    box-shadow: 0 1px 3px var(--shadow-color);
}

.header-title-container {
    display: flex;
    align-items: baseline;
    gap: 1.2rem;
    flex-wrap: wrap;
}

h1 {
    margin: 0;
    font-size: 1.8rem;
    font-weight: 700;
}

.year-info {
    font-size: 1.2rem;
    color: var(--secondary-text-color);
    font-weight: 500;
}

.year-selector {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.year-select-group {
    display: flex;
    align-items: center;
    gap: 1rem;
    white-space: nowrap;
}

.select-item {
    display: flex;
    align-items: center;
    white-space: nowrap;
}

.year-selector label {
    margin-right: 0.5rem;
    font-size: 1rem;
    white-space: nowrap;
}

#year, #country {
    background-color: var(--bg-color);
    color: var(--primary-text-color);
    border: 1px solid var(--border-color);
    padding: 0.5rem;
    border-radius: 4px;
    font-size: 1rem;
    white-space: nowrap;
    cursor: pointer;
}

.year-btn-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}

.today-year-btn {
    background-color: var(--bg-color);
    color: var(--primary-text-color);
    border: 1px solid var(--border-color);
    padding: 0.5rem 0.8rem;
    border-radius: 4px;
    font-size: 1rem;
    font-family: inherit;
    cursor: pointer;
    white-space: nowrap;
    transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.today-year-btn:hover {
    background-color: var(--primary-text-color);
    color: var(--bg-color);
}

.lang-toggle {
    background-color: var(--bg-color);
    color: var(--primary-text-color);
    border: 1px solid var(--border-color);
    padding: 0.5rem 0.8rem;
    border-radius: 4px;
    font-size: 0.95rem;
    font-family: inherit;
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
    transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.lang-toggle:hover {
    background-color: var(--primary-text-color);
    color: var(--bg-color);
}

.theme-toggle {
    background-color: var(--bg-color);
    color: var(--primary-text-color);
    border: 1px solid var(--border-color);
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
    font-size: 1.1rem;
    line-height: 1;
    font-family: inherit;
    cursor: pointer;
    white-space: nowrap;
    transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--primary-text-color);
    color: var(--bg-color);
}

#calendar-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
}

.month-container {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.8rem;
    background-color: var(--header-bg-color);
    box-sizing: border-box;
    box-shadow: 0 1px 3px var(--shadow-color);
}

.month-header {
    text-align: center;
    font-size: 1.2rem;
    font-weight: 400;
    margin-bottom: 0.8rem;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 4px;
    text-align: center;
}

.day-header {
    font-weight: 700;
    font-size: 0.8rem;
    color: var(--secondary-text-color);
}

.day {
    padding: 0.2rem;
    font-size: 0.8rem;
    border-radius: 4px;
    position: relative;
    cursor: pointer;
    transition: background-color 0.15s ease;
}

.day:hover {
    background-color: var(--hover-bg-color);
}

.day.selected {
    outline: 2px solid var(--primary-text-color);
    outline-offset: -1px;
    background-color: var(--hover-bg-color);
}

.day:hover, .day.selected {
    z-index: 25;
}

.day.sunday, .day-header.sunday {
    color: var(--sunday-color);
}

.day.saturday, .day-header.saturday {
    color: var(--saturday-color);
}

.day.today {
    background-color: var(--primary-text-color);
    color: var(--bg-color) !important; /* Important to override other color rules */
    font-weight: 700;
    border-radius: 50%;
}

.day.holiday {
    color: var(--holiday-color);
    font-weight: 700;
}

.tooltip:hover::after,
.tooltip.active::after {
    opacity: 1;
    visibility: visible;
    transform: translateY(-5px) translateX(-50%);
}

.tooltip:hover::before,
.tooltip.active::before {
    opacity: 1;
    visibility: visible;
    transform: translateY(-5px) translateX(-50%);
}

.tooltip::before {
    content: '';
    position: absolute;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    border-width: 5px;
    border-style: solid;
    border-color: var(--primary-text-color) transparent transparent transparent;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: 30;
    pointer-events: none;
}

.tooltip::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(125% + 5px);
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--primary-text-color);
    color: var(--bg-color);
    padding: 6px 10px;
    border-radius: 6px;
    font-size: 0.8rem;
    line-height: 1.35;
    text-align: center;
    white-space: pre;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: 30;
    pointer-events: none;
    box-shadow: 0 2px 8px var(--shadow-color);
}

.day.col-sun::after {
    left: 0;
    transform: translateX(0);
}

.day.col-sun.tooltip:hover::after,
.day.col-sun.tooltip.active::after {
    transform: translateY(-5px) translateX(0);
}

.day.col-sat::after {
    left: auto;
    right: 0;
    transform: translateX(0);
}

.day.col-sat.tooltip:hover::after,
.day.col-sat.tooltip.active::after {
    transform: translateY(-5px) translateX(0);
}

footer {
    text-align: center;
    margin-top: 2rem;
    padding: 1rem;
    color: var(--secondary-text-color);
    font-size: 0.9rem;
}

.holiday-note {
    margin-bottom: 0.8rem;
    font-size: 0.85rem;
    color: var(--secondary-text-color);
    line-height: 1.5;
}

/* Responsive Design */
@media (min-width: 1800px) {
    #calendar-container {
        grid-template-columns: repeat(6, 1fr);
    }
}

@media (min-width: 1200px) and (max-width: 1799px) {
    #calendar-container {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        padding: 1rem 0.8rem;
    }
    .header-title-container {
        flex-direction: column;
        align-items: center;
        width: 100%;
        gap: 0.3rem;
        margin-bottom: 0.8rem;
    }
    h1 {
        font-size: 1.5rem;
        width: 100%;
        text-align: center;
        margin-bottom: 0;
    }
    .year-info {
        font-size: 1.05rem;
        text-align: center;
    }
    .year-selector {
        justify-content: center;
        width: 100%;
        gap: 0.5rem;
    }
    .year-select-group {
        justify-content: center;
    }
    .year-btn-group {
        justify-content: center;
    }
    #calendar-container {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    }
}

@media (max-width: 480px) {
    body {
        padding: 0.4rem;
    }
    header {
        padding: 0.8rem 0.5rem;
    }
    .year-selector {
        gap: 0.4rem;
    }
    .year-select-group {
        gap: 0.6rem;
        flex-wrap: wrap;
        justify-content: center;
    }
    .year-selector label {
        font-size: 0.9rem;
        margin-right: 0.3rem;
    }
    #year, #country {
        padding: 0.4rem 0.4rem;
        font-size: 0.9rem;
    }
    #country {
        max-width: 120px;
    }
    #year {
        max-width: 145px;
    }
    .today-year-btn {
        padding: 0.4rem 0.6rem;
        font-size: 0.9rem;
    }
    .lang-toggle {
        padding: 0.4rem 0.6rem;
        font-size: 0.85rem;
    }
    .theme-toggle {
        padding: 0.4rem 0.6rem;
        font-size: 1rem;
    }
    #calendar-container {
        grid-template-columns: 1fr;
    }
}