:root {
  /* WhatsApp Default Theme */
  --bg-color: #0b141a;
  --text-color: #e9edef;
  --hint-color: #8696a0;
  --secondary-bg: #202c33;
  --input-bg: #2a3942;
  --border-color: #3d4a52;
  --btn-bg: #00a884;
  --btn-text: #111b21;
  --sys-msg-bg: #182229;
  --msg-in-bg: #202c33;
  --msg-out-bg: #005c4b;
  --msg-out-text: #e9edef;
  --header-bg: #202c33;
  --chat-bg-img: url('https://user-images.githubusercontent.com/15075759/28719144-86dc0f70-73b1-11e7-911d-60d70fcded21.png');
  --accent: #53bdeb;
}

body.tg-theme {
  /* Telegram WebApp Theme */
  --bg-color: var(--tg-theme-bg-color, #ffffff);
  --text-color: var(--tg-theme-text-color, #222222);
  --hint-color: var(--tg-theme-hint-color, #999999);
  --secondary-bg: var(--tg-theme-secondary-bg-color, #f4f4f5);
  --input-bg: var(--tg-theme-bg-color, #ffffff);
  --border-color: var(--tg-theme-hint-color, #cccccc);
  --btn-bg: var(--tg-theme-button-color, #3390ec);
  --btn-text: var(--tg-theme-button-text-color, #ffffff);
  --sys-msg-bg: var(--tg-theme-secondary-bg-color, #f4f4f5);
  --msg-in-bg: var(--tg-theme-bg-color, #ffffff);
  --msg-out-bg: var(--tg-theme-button-color, #3390ec);
  --msg-out-text: var(--tg-theme-button-text-color, #ffffff);
  --header-bg: var(--tg-theme-header-bg-color, #ffffff);
  --chat-bg-img: none;
  --accent: var(--tg-theme-link-color, #3390ec);
}

/* Telegram Specific UI Overrides */
body.tg-theme .chat-body { background-color: var(--secondary-bg); background-blend-mode: normal; }
body.tg-theme .msg-in { border-radius: 12px 12px 12px 4px; border: none; box-shadow: 0 1px 2px rgba(0,0,0,0.1); margin-bottom: 4px; }
body.tg-theme .msg-out { border-radius: 12px 12px 4px 12px; border: none; box-shadow: 0 1px 2px rgba(0,0,0,0.1); margin-bottom: 4px; }
body.tg-theme .chat-header { box-shadow: none; border-bottom: 1px solid var(--border-color); }
body.tg-theme .back-btn { display: none !important; }
body.tg-theme .ticks { color: var(--msg-out-text); opacity: 0.8; }
body.tg-theme .upload-container { border: 1px solid var(--border-color); box-shadow: none; }
body.tg-theme .sys-msg { background: rgba(0,0,0,0.05); color: var(--text-color); box-shadow: none; }

* { box-sizing: border-box; margin: 0; padding: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
body { background-color: var(--bg-color); color: var(--text-color); display: flex; justify-content: center; height: 100vh; overflow: hidden; }

#upload-screen { display: flex; flex-direction: column; align-items: center; justify-content: center; height: 100vh; width: 100%; }
.upload-container { background: var(--secondary-bg); padding: 30px; border-radius: 12px; text-align: center; max-width: 400px; box-shadow: 0 4px 15px rgba(0,0,0,0.3); }
.upload-container h2 { margin-bottom: 10px; font-weight: 500; }
.upload-container p { color: var(--hint-color); margin-bottom: 20px; font-size: 14px; }
input[type="file"] { background: var(--input-bg); padding: 10px; border-radius: 8px; width: 100%; margin-bottom: 20px; color: var(--text-color); border: 1px solid var(--border-color); }
#sender-selection h3 { font-size: 16px; margin-bottom: 5px; }
select { width: 100%; padding: 10px; background: var(--input-bg); color: var(--text-color); border: 1px solid var(--border-color); border-radius: 8px; margin-bottom: 15px; font-size: 15px; }
button.native-btn { background: var(--btn-bg); color: var(--btn-text); border: none; padding: 12px 20px; border-radius: 8px; cursor: pointer; font-weight: bold; width: 100%; font-size: 15px; }

#chat-screen { display: flex; flex-direction: column; width: 100%; max-width: 800px; height: 100vh; background-color: var(--bg-color); border-left: 1px solid var(--secondary-bg); border-right: 1px solid var(--secondary-bg); }
.chat-header { background-color: var(--header-bg); padding: 10px 16px; display: flex; align-items: center; height: 60px; z-index: 10; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.back-btn { font-size: 22px; cursor: pointer; margin-right: 15px; color: var(--hint-color); padding: 5px; }
.avatar { background: var(--hint-color); border-radius: 50%; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; margin-right: 15px; overflow: hidden; }
.contact-info { flex-grow: 1; font-weight: 500; font-size: 16px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: var(--text-color); }
.header-actions { display: flex; gap: 20px; align-items: center; }
.header-actions svg { fill: var(--hint-color); }

.chat-body { flex-grow: 1; overflow-y: auto; padding: 20px 5%; display: flex; flex-direction: column; gap: 4px; background-image: var(--chat-bg-img); background-color: var(--bg-color); background-blend-mode: multiply; }
.sys-msg { background-color: var(--sys-msg-bg); color: var(--hint-color); padding: 6px 12px; border-radius: 8px; font-size: 12.5px; align-self: center; text-align: center; margin: 10px 0; max-width: 90%; box-shadow: 0 1px 1px rgba(0,0,0,0.1); }
.date-msg { text-transform: uppercase; font-size: 12px; }

.msg { max-width: 75%; padding: 6px 7px 8px 9px; border-radius: 12px; position: relative; font-size: 14.2px; line-height: 19px; display: flex; flex-direction: column; word-wrap: break-word; box-shadow: 0 1px 1px rgba(0,0,0,0.1); margin-bottom: 2px; }
.msg-in { align-self: flex-start; background-color: var(--msg-in-bg); border-top-left-radius: 0; color: var(--text-color); border: 1px solid var(--secondary-bg); }
.msg-out { align-self: flex-end; background-color: var(--msg-out-bg); border-top-right-radius: 0; color: var(--msg-out-text); }
.msg-text { white-space: pre-wrap; margin-bottom: 2px; }
.msg-time { font-size: 11px; opacity: 0.7; align-self: flex-end; margin-top: -10px; margin-bottom: -4px; float: right; display: flex; align-items: center; gap: 3px; margin-left: 10px; }
.ticks { color: var(--accent); font-size: 13px; }

.sender-name { font-size: 13px; font-weight: 500; color: var(--accent); margin-bottom: 2px; }
.chat-footer { background-color: var(--header-bg); padding: 12px 16px; display: flex; justify-content: center; align-items: center; min-height: 62px; }
.read-only-msg { background-color: var(--secondary-bg); color: var(--hint-color); padding: 12px 15px; border-radius: 8px; font-size: 14px; text-align: center; width: 100%; }

.poll-container { display: flex; background: rgba(0,0,0,0.05); border-radius: 8px; padding: 10px; margin-top: 5px; min-width: 250px; }
.poll-icon { font-size: 20px; margin-right: 10px; opacity: 0.7; }
.poll-content { flex: 1; }
.poll-question { font-weight: bold; margin-bottom: 12px; }
.poll-option { margin-bottom: 8px; }
.poll-option-row { display: flex; align-items: center; margin-bottom: 4px; }
.poll-radio { width: 20px; height: 20px; border: 2px solid var(--accent); border-radius: 50%; margin-right: 12px; position: relative; box-sizing: border-box; }
.poll-radio.selected::after { content: ''; position: absolute; top: 3px; left: 3px; width: 10px; height: 10px; background: var(--accent); border-radius: 50%; }
.poll-option-text { flex: 1; font-size: 14.5px; }
.poll-progress-bar { height: 4px; background: rgba(0,0,0,0.1); border-radius: 2px; overflow: hidden; margin-left: 24px; }
.poll-progress-fill { height: 100%; background: var(--accent); border-radius: 2px; }