/* ===========================
   CSS Variables
   =========================== */
:root {
    --color-primary: #06C755;
    --color-primary-dark: #05a648;
    --color-primary-light: #e8f9ef;
    --color-error: #e53935;
    --color-error-light: #fdecea;
    --color-success: #06C755;
    --color-success-light: #e8f9ef;
    --color-info: #1976d2;
    --color-info-light: #e3f2fd;
    --color-text: #333333;
    --color-text-secondary: #888888;
    --color-bg: #f0f0f0;
    --color-white: #ffffff;
    --color-border: #e0e0e0;
    --color-nav-bg: #ffffff;
    --color-nav-border: #e0e0e0;
    --color-chat-bg: #9bbbd4;
    --color-bubble-mine: #06C755;
    --color-bubble-theirs: #ffffff;
    --color-unread-badge: #ff3b30;
    --nav-height: 60px;
    --border-radius: 8px;
    --border-radius-lg: 16px;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.12);
}

/* ===========================
   Reset & Base
   =========================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    height: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
                 "Hiragino Sans", "Hiragino Kaku Gothic ProN",
                 "Yu Gothic", "Meiryo", sans-serif;
    font-size: 14px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    height: 100%;
    padding-bottom: var(--nav-height);
}

body:not(:has(.bottom-nav)) {
    padding-bottom: 0;
}

a {
    color: var(--color-primary);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

button {
    cursor: pointer;
    font-family: inherit;
    font-size: inherit;
    border: none;
    background: none;
}

/* ===========================
   Flash Messages
   =========================== */
.flash-container {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 4px;
    pointer-events: none;
}

.flash {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    font-size: 14px;
    font-weight: 500;
    pointer-events: auto;
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.flash--error {
    background-color: var(--color-error);
    color: var(--color-white);
}

.flash--success {
    background-color: var(--color-success);
    color: var(--color-white);
}

.flash--info {
    background-color: var(--color-info);
    color: var(--color-white);
}

.flash__message {
    flex: 1;
    text-align: center;
}

/* ===========================
   Main Content
   =========================== */
.main-content {
    min-height: calc(100vh - var(--nav-height));
}

/* ===========================
   Bottom Navigation
   =========================== */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background-color: var(--color-nav-bg);
    border-top: 1px solid var(--color-nav-border);
    display: flex;
    align-items: stretch;
    z-index: 900;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.06);
}

.bottom-nav__item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 11px;
    font-weight: 500;
    padding: 6px 0;
    transition: color 0.15s ease;
    position: relative;
}

.bottom-nav__item:hover {
    color: var(--color-primary);
    text-decoration: none;
}

.bottom-nav__item--active {
    color: var(--color-primary);
}

.bottom-nav__item--active::after {
    content: "";
    position: absolute;
    top: 0;
    left: 25%;
    right: 25%;
    height: 2px;
    background-color: var(--color-primary);
    border-radius: 0 0 2px 2px;
}

.bottom-nav__item--button {
    width: 100%;
    background: none;
    border: none;
    padding: 6px 0;
}

.bottom-nav__logout-form {
    flex: 1;
    display: flex;
}

.bottom-nav__logout-form .bottom-nav__item--button {
    flex: 1;
}

.bottom-nav__icon {
    width: 24px;
    height: 24px;
    fill: currentColor;
}

.bottom-nav__label {
    line-height: 1;
}

/* ===========================
   Auth Pages
   =========================== */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, #06C755 0%, #05a848 40%, #f0f0f0 40%);
    padding: 24px 16px;
}

.auth-container {
    width: 100%;
    max-width: 400px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

.auth-logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding-top: 16px;
}

.auth-logo__icon {
    width: 72px;
    height: 72px;
    filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.2));
}

.auth-logo__icon svg {
    width: 100%;
    height: 100%;
}

.auth-logo__title {
    font-size: 26px;
    font-weight: 700;
    color: var(--color-white);
    letter-spacing: 0.5px;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
}

.auth-logo__subtitle {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.85);
    font-weight: 500;
    margin-top: -4px;
}

.auth-card {
    width: 100%;
    background-color: var(--color-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 28px 24px;
}

.auth-footer {
    text-align: center;
}

.auth-footer__text {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.auth-footer__link {
    color: var(--color-primary);
    font-weight: 600;
}

.auth-footer__link:hover {
    text-decoration: underline;
}

/* ===========================
   Form Elements
   =========================== */
.auth-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-label {
    font-size: 13px;
    font-weight: 600;
    color: var(--color-text);
}

.form-input {
    width: 100%;
    padding: 12px 14px;
    font-size: 15px;
    font-family: inherit;
    color: var(--color-text);
    background-color: var(--color-white);
    border: 1.5px solid var(--color-border);
    border-radius: var(--border-radius);
    outline: none;
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
    -webkit-appearance: none;
    appearance: none;
}

.form-input::placeholder {
    color: #aaaaaa;
}

.form-input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(6, 199, 85, 0.15);
}

/* ===========================
   Buttons
   =========================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 13px 20px;
    font-size: 15px;
    font-weight: 600;
    font-family: inherit;
    border-radius: var(--border-radius);
    border: none;
    cursor: pointer;
    transition: background-color 0.15s ease, opacity 0.15s ease, transform 0.1s ease;
    letter-spacing: 0.3px;
    -webkit-appearance: none;
    appearance: none;
}

.btn:active {
    transform: scale(0.98);
}

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

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

.btn--full {
    width: 100%;
    margin-top: 8px;
}

/* ===========================
   Room List (Chat Index)
   =========================== */
.room-list {
    max-width: 600px;
    margin: 0 auto;
    padding: 8px 16px;
}

.room-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 12px;
    background-color: var(--color-white);
    border-bottom: 1px solid #f0f0f0;
    text-decoration: none;
    color: inherit;
    transition: background-color 0.1s ease;
}

.room-card:first-child {
    border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.room-card:last-child {
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    border-bottom: none;
}

.room-card:only-child {
    border-radius: var(--border-radius);
}

.room-card:hover {
    background-color: #fafafa;
    text-decoration: none;
}

.room-card__avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--color-primary);
    color: var(--color-white);
    font-size: 20px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.room-card__body {
    flex: 1;
    min-width: 0;
}

.room-card__header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 4px;
}

.room-card__name {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.room-card__time {
    font-size: 12px;
    color: var(--color-text-secondary);
    flex-shrink: 0;
}

.room-card__footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.room-card__preview {
    font-size: 13px;
    color: var(--color-text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
}

.room-card__preview--empty {
    color: #bbbbbb;
    font-style: italic;
}

.room-card__badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 20px;
    height: 20px;
    padding: 0 6px;
    background-color: var(--color-unread-badge);
    color: var(--color-white);
    font-size: 11px;
    font-weight: 700;
    border-radius: 10px;
    flex-shrink: 0;
    line-height: 1;
}

/* ===========================
   Empty State
   =========================== */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 60px 16px;
    gap: 16px;
    color: #bbbbbb;
}

.empty-state__icon svg {
    width: 48px;
    height: 48px;
    fill: #cccccc;
}

.empty-state__text {
    font-size: 14px;
    color: #999999;
    text-align: center;
    line-height: 1.7;
}

/* ===========================
   Chat Room
   =========================== */
.chat-room {
    display: flex;
    flex-direction: column;
    /* 下部固定ナビ(.bottom-nav)の高さ分を差し引き、
       メッセージ入力欄(.chat-footer)がナビに隠れて操作できなくなるのを防ぐ */
    height: calc(100vh - var(--nav-height));
    height: calc(100dvh - var(--nav-height));
    max-width: 600px;
    margin: 0 auto;
    background-color: var(--color-chat-bg);
}

.chat-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    flex-shrink: 0;
    z-index: 10;
}

.chat-header__back {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    color: var(--color-text);
    flex-shrink: 0;
}

.chat-header__back svg {
    width: 24px;
    height: 24px;
}

.chat-header__back:hover {
    text-decoration: none;
    color: var(--color-primary);
}

.chat-header__avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: var(--color-primary);
    color: var(--color-white);
    font-size: 16px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.chat-header__name {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text);
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Chat Messages Area */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Message Bubbles */
.message {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    max-width: 80%;
}

.message--mine {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.message--theirs {
    align-self: flex-start;
}

.message__avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background-color: var(--color-primary);
    color: var(--color-white);
    font-size: 13px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.message__content-wrap {
    display: flex;
    align-items: flex-end;
    gap: 6px;
}

.message--mine .message__content-wrap {
    flex-direction: row-reverse;
}

.message__bubble {
    padding: 10px 14px;
    font-size: 14px;
    line-height: 1.5;
    word-break: break-word;
    white-space: pre-wrap;
}

.message__bubble--mine {
    background-color: var(--color-bubble-mine);
    color: var(--color-white);
    border-radius: 18px 18px 4px 18px;
}

.message__bubble--theirs {
    background-color: var(--color-bubble-theirs);
    color: var(--color-text);
    border-radius: 18px 18px 18px 4px;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}

.message__time {
    font-size: 11px;
    color: rgba(255, 255, 255, 0.7);
    flex-shrink: 0;
    white-space: nowrap;
}

.message--theirs .message__time {
    color: rgba(0, 0, 0, 0.4);
}

/* Chat Footer / Input */
.chat-footer {
    padding: 8px 12px;
    background-color: var(--color-white);
    border-top: 1px solid var(--color-border);
    flex-shrink: 0;
}

.chat-form {
    display: flex;
    align-items: center;
    gap: 8px;
}

.chat-form__input {
    flex: 1;
    padding: 10px 16px;
    font-size: 14px;
    font-family: inherit;
    color: var(--color-text);
    background-color: #f6f6f6;
    border: 1px solid var(--color-border);
    border-radius: 24px;
    outline: none;
    transition: border-color 0.15s ease;
}

.chat-form__input:focus {
    border-color: var(--color-primary);
    background-color: var(--color-white);
}

.chat-form__send-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--color-primary);
    color: var(--color-white);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: background-color 0.15s ease;
}

.chat-form__send-btn:hover {
    background-color: var(--color-primary-dark);
}

.chat-form__send-btn svg {
    width: 20px;
    height: 20px;
}

/* ===========================
   Page Header (Chat List)
   =========================== */
.page-header {
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    padding: 14px 16px;
    position: sticky;
    top: 0;
    z-index: 100;
    text-align: center;
}

.page-header__title {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text);
}

/* ===========================
   Friends Page
   =========================== */
.friends-page {
    max-width: 600px;
    margin: 0 auto;
    padding: 16px;
}

/* Search bar */
.search-section {
    margin-bottom: 20px;
}

.search-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 12px;
    color: #aaaaaa;
    display: flex;
    align-items: center;
}

.search-input {
    width: 100%;
    padding: 10px 12px 10px 40px;
    border: 1.5px solid var(--color-border);
    border-radius: 24px;
    font-size: 14px;
    font-family: inherit;
    background-color: #f6f6f6;
    outline: none;
    transition: border-color 0.2s ease, background-color 0.2s ease;
    -webkit-appearance: none;
    appearance: none;
}

.search-input:focus {
    border-color: var(--color-primary);
    background-color: var(--color-white);
    box-shadow: 0 0 0 3px rgba(6, 199, 85, 0.12);
}

/* Tabs */
.tabs-section {
    margin-top: 8px;
}

.tab-bar {
    display: flex;
    border-bottom: 2px solid #e8e8e8;
    margin-bottom: 16px;
}

.tab-btn {
    flex: 1;
    padding: 10px 8px;
    background: none;
    border: none;
    font-size: 14px;
    font-weight: 500;
    font-family: inherit;
    color: var(--color-text-secondary);
    cursor: pointer;
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    transition: color 0.2s ease;
}

.tab-btn::after {
    content: "";
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: transparent;
    transition: background-color 0.2s ease;
}

.tab-btn--active {
    color: var(--color-primary);
}

.tab-btn--active::after {
    background-color: var(--color-primary);
}

.tab-btn:hover {
    color: var(--color-primary);
}

/* Notification badge (friends / requests) */
.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 18px;
    height: 18px;
    padding: 0 5px;
    background-color: var(--color-unread-badge);
    color: var(--color-white);
    font-size: 11px;
    font-weight: 700;
    border-radius: 9px;
    line-height: 1;
}

/* Friend cards */
.friend-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.friend-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    background-color: var(--color-white);
    border: 1px solid #eeeeee;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

.friend-card__avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: var(--color-primary);
    color: var(--color-white);
    font-size: 18px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    text-transform: uppercase;
}

.friend-card__info {
    flex: 1;
    min-width: 0;
}

.friend-card__name {
    margin: 0 0 2px;
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.friend-card__id {
    margin: 0;
    font-size: 12px;
    color: var(--color-text-secondary);
}

.friend-card__actions {
    flex-shrink: 0;
}

/* Small button variant for friend cards */
.btn--sm {
    padding: 6px 16px;
    font-size: 13px;
    border-radius: 20px;
}

/* Search results area */
#search-results .friend-list {
    margin-bottom: 16px;
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 480px) {
    .auth-page {
        padding: 16px 12px;
        align-items: flex-start;
        padding-top: 40px;
    }

    .auth-card {
        padding: 24px 16px;
    }

    .auth-logo__title {
        font-size: 22px;
    }

    .auth-logo__icon {
        width: 60px;
        height: 60px;
    }
}

@media (min-width: 768px) {
    body {
        font-size: 15px;
    }

    .bottom-nav {
        max-width: 600px;
        left: 50%;
        transform: translateX(-50%);
        border-radius: var(--border-radius) var(--border-radius) 0 0;
        border-left: 1px solid var(--color-nav-border);
        border-right: 1px solid var(--color-nav-border);
    }
}